Abstract: Five years have passed since the First International Symposium on High Intensity Focused Ultrasound Application in Medicine held in Chongqing,China,and the founding of the International Society of Therapeutic Ultrasound in 2001.HIFU has undergone rapid development over the past five years.This article describes main differences between the HIFU surgery and the traditional ultrasound thermo-therapy,introduces the progresses made in HIFU techniques,the basics of ultrasound bio-physics,clinic applications of HIFU,as well as the international academic activities in HIFU.In particular,contributions made by Chinese scholars are introduced,and the future challenges faced discussed.