He composed the immortal revolutionary hymn "Song of General Kim Il Sung" and the national anthem of the DPRK.

Before the liberation of Korea from Japan's colonial rule, he had been a day laborer. It was after the national liberation by President Kim Il Sung (August 15, 1945) that he could realize his hope and display his talent.

The next day after the liberation, he composed "March of Korea", the first song of new Korea and his maiden work.

Looking up to President Kim Il Sung delivering a speech on his triumphal return on October 14, Juche 34 (1945), he felt a strong impulse to sing in praise of the President.

In 1946, he composed "Song of General Kim Il Sung" as a popular hymn in reflection of all the people's admiration, veneration, absolute trust and ardent loyalty to the President. And in 1947, he produced the national anthem "The Patriotic Song" representing the people's mission, love, devotion and oath for the country to be prosperous under the guidance of the President as well as their prayer for the future of the country.

In his lifetime, Kim Won Gyun made distinguished feats for the development of the country's music, produced many famous songs of high ideological and artistic value and contributed to the creation of Sea of Blood-type revolutionary operas and the training of musician reserves.

A decree of the Presidium of the DPRK Supreme People's Assembly on giving his name to Pyongyang Conservatory was issued in June 2006, and his bust was built in front of the main building of Pyongyang Kim Won Gyun Conservatory.