The establishment of the modern Police organization dates back to July 19, 1921. On July 19, 1921, the Sixth Session of the People’s Parliament of Mongolia resolved to establish the “Preventive Militia”, mandated with the modern police functions, to ensure implementation of the law, fight crime, and to maintain public order.

Since 1921 untill1990s, the police organization belonged to Ministry of Interior and Ministry of Public Security to enforce the law, ensure public safety, and to fight crime in metropolitan and local areas with integrated organizational management and preformed state mandated responsibilities with public participation.

As a result of the political and socioeconomic transitions towards democracy and market economy in 1990s, Mongolian police organization underwent to a drastic transformation and has been reestablished as a National Police Agency- Regulatory Agency of the Government of Mongolia mandated to combat crime, maintain public order and public safety on a national basis.

History of internal troops

The Internal Troopers, originating from Genghis Khan's royal guard, formed by the Partisans from the People's Revolution in 1922 to fulfill the role of internal security, honorably have been carrying out the tasks entrusted to them by government and command to this day. 

The Internal Troopers are specialized military unit that independently operates in peacetime and have special functions of national security.

The internal troop is:

- Special platoon since 1922,

- Special unit since 1924,

- Headquarters, Special Division since 1929

- Headquarters, Special Regiment since 1936

During this period, the Internal Troopers have been tasked specifically to fight counter-revolutionary forces, participating in the suppression of rebellion, guarding the capital's offices and prisons, delivering important letters and correspondence in certain provinces and remote areas from the center.

Since 1936, the Internal Troops were structured under the Ministry of Internal Affairs

On November 5, 1930, at a meeting of the Military Council order No. 133, the Special Division of Internal Troop was reorganized into a Special Regiment.

The Internal Affairs Office sent its own representative to the mobilization commission to oversee the recruitment of all military councils to serve in the Internal Troopers, and to recruit a new, healthy, body of military service that would be politically competent.

With the newly formed government and the deepening of religious influence over the general population, the revolutionary movement and the armed rebellion were formed everywhere. The Internal Troops honorably fulfilled the fierce and life-threatening task of subduing hostile activities such as the killing of local government officials and election activists, burning public institutions, including the folk cooperatives and schools, and evacuation of local people within the border illegally. 

According to the historical records of the armed conflicts in east and west border in late 1930’s, multiple confrontations, the Khalkhin Gol battle, the hard years of 1940-1945, and the Liberation War of 1945, the importance of Internal Troops became more evident and structurally has been strengthened. Since then, the main duty of the Internal Troop was deployed in two areas as defense and guard.

One of the defining facts was that the establishment of a special military regiment for the protection of captives according to the order of the Minister of Internal Affairs No. 429 and Resolution of the Council of Ministers No. 24 on October 30, 1945 on the. The function of this regiment was to organize the captives in the rebuilding of the city and the restoration of their war-torn farming. 

In addition, the Internal special regiment has performed duties as a guard and security at the focal points within the country while providing security for winter camp belongs to Marshal Kh. Choibalsan’s and when he is in the remote area as well as for the Embassy and Trade representative's office of the Soviet Union within the 24 hours.

In 1940s, the main roles of Internal special regiment were the guarding the focal points within the country and providing the security for Marshal Kh.Choibalsan’s trip and his residences. As well as providing the guard for the Embassy and Trade representative's office of the Soviet Union along with taking a control for captives of the Japanese military when mobilizing them for rebuilding the public farming which destroyed by war.  

In 1950s, the main roles of internal special regiment were the providing security for state high-level visits from foreign countries. In addition, guarding the facilities such as Memorial mausoleum of D.Sukhbaatar and Kh.Choibalsan, Prime Minister's winter camp, Bayangol Camp, Guesthouses in Ikh Tenger and Baga Tenger valleys, Food Laboratory, Correctional institutions Ministry of Internal Affairs, Central warehouse, Gas stations belong Government and Ministry of Internal Affairs, State archive, Central prison, and Prison Camp at Tsagaan Khuaran. 

Since 1959, the Internal Troops have served in the Border and Internal Troops Division of the Public Security Department.

Internal Troops has been provided by security for delegations during the state high-level visits from foreign countries in the 1950s. From the mid-1950's onward, the external and internal situation of country has stabilized and its security services were broken into three branches.

A /. The high importance objects of the state:

B /. Garrison installations:

B /. Armored protection of the garrisons.

The role of the Internal Troops in the military and in the reconstruction of the country, in the protection of important objects of the state, discipline and their achievements in military and political preparation, were highly appreciated. 

In 1932, Internal Troops were awarded the Order of Merit of the 1st Degree, took the 1st place and the red flag on the competition held in the 20th anniversary of the People's Revolution in 1941 between Border and Internal troops units and won it for five consecutive years. By the Decree of the leaders of the State Conference No. 50 dated July 10, 1946, was named after Commander D. Sukhbaatar, and was awarded the Order of D. Sukhbaatar on July 17, 1957 for the 35th anniversary of the Ministry of Internal Affairs.

In 1972, in honor of the 50th anniversary of the Ministry of Internal Affairs, a special regiment was awarded the Order of the Red Banner of Labor from the leaders of the People's Parliament.

By Decree of the Council of Ministers No. 239 of December 31, 1986, the state facilities to be protected by the Internal Troops were defined.

The Internal Troops also fulfilled reinforcement duty in law enforcement at public events such as national holidays and mass gatherings by decision of the Ministry of Public Security when there is a shortage of police.

The Internal Troops have been guarding power plants, the Mining Concentration Plant "Erdenet", reservoirs, gold mines, and special disciplinary institutions in the 1980's.

Under National Police Agency since 1990

In 1990, the Ministry of Public Security was disbanded, along with the National Police Agency was established as an independent organization and the Internal Troops structurally transferred to perform its security duties.

To assist the NPA, the Internal Troops have now been in charge of conducting the implementation of quarantine procedures in case of various infectious diseases in public events (social, political, cultural, sports and others), suppressing and eliminating activities that violate the public order in the central settlement areas, protecting state property from the fire and various natural hazards. Also, obliged to enforce rules and regulations for the discipline of the protected labor colonies. 

            Since 1990, the structure and organization of the Internal Troops have been changed with several legal reforms. Within the approval of the Internal Military Law in 1995, the objectives, duties, and legal basis of the internal military operations have been legalized. But the Parliament of Mongolia has discussed and approved the “Law of revocation of the Internal Troops”, on January 16, 2014 to combine Internal Troops, which has more than 90 years of history, to the Police Force with its staff, equipment, budget, and the functions that were implemented on April 01, 2014.

The Parliament of Mongolia re-approved the Law of Internal Troops and legalized the functions and legal basis of the Internal troops on February of 2017. The enacted law is started to enforce from September 01, 2017 and Internal Troops has been honorably fulfilling its obligations under the law.