In 1957 at yonsei university, there were series of meetings held among the music students of the late Dr. La Unyong. The purpose of the meetings were studying and promoting comtemporary music. And Park Jaeyol, an Ameritus Professor of Yonsei University and the first president then, founded The Korean Society of the 21st Century Music under the name of "Late Century Music Society".
In 1969, as it changed its name to "Yonsei Composition Studies", the society has given public performances of new works and has hosted seminars as its main activities. And since then, the society became the front runner in comtemporary music society in Korea and changed its name to "20th Century Contemporary Studies", and to the present name, "The Korean Society of the 21st Century Music".

The society has been the leader among the comtemporary music organizations in Korea and it has promoted contemporary music for last 40 years. It consists of more than 100 composers in and out of Korea and they participate in various activities, like at least two regular concerts, seminars, as well as publishing and recording music.

Many prominent ensemble groups, like Seoul Solist, the National Chorus of Korea, Korean Festival Ensemble, as well as Koji Ensemble of Japan have performed for the society and have worked together with performers of the society for better understanding and researching of comtemporary music. The society also hosts symposiums, chamber music concerts, like ones for the traditional Korean instruments, to promote Korean music to the rest of the world.

In order to elevate the level of understanding of comtemporary music, the society has constantly worked out and supported programs like, "Performance in Performances", basically a co-work program with other genre, "Seoul International Competition for Composers" which promotes and leads the trend of world music, "MUSIC TODAY, SEOUL" an international comtemporary music festival, as well as international exchange music concerts and workshops with Earport Music Foundation in Germany.