Kung was born in 1961 and raised in Hong Kong. He studied classical music and composition in the United States with Allen Trubitt and George Crumb. He focuses on experimentation with different types of music and art forms. 

In 1987, Kung and Peter Suart founded a theatrical music ensemble 'the box' in Hong Kong. The band occupies an unusual position in Hong Kong culture, one which straddles popular and experimental forms.

Since 1996 he has created, composed and staged four full-length music theatre pieces: Destiny Travels Limited, The Floating Bridge, City Inside a Broken Sky and M Garden. He has collaborated frequently with choreographers and theatre artists, and has performed his music in Hong Kong, Taiwan, Japan, Cuba, Tashkent, New York, London, Berlin and Venice. Kung’s recordings on CD include Destiny Travels Limited and Bluesilence/Fishdreams. Kung is currently involved with actively supporting independent musicians and organising 'Open Music' programmes on the streets of Hong Kong. 

龔志成1961年在香港出生，之後在美跟隨Allen Trubitt及George Crumb學習古典音樂及作曲。八十年代中回港後與 彼得小話成立音樂組合「盒子」。過往十多年，龔氏作過不同的音樂風格、即興創作和進行戲劇藝術的實驗。其個 人音樂劇場作品包括《行行重行行》、《浮橋》、《迷走都市》及《M園》，並為本地多位編舞家及劇場導演創作音樂。他曾在香港、台灣、日本、古巴、塔什干、紐約、倫敦、柏林、威尼斯演出自己的音樂。專輯有《行行重行行》，及《Bluesilence / Fishdreams》。近年，龔志成積極策劃「開放音樂」活動，支持獨立音樂人。