HEVC(High Efficient Video Coding) becomes the hot area in the world's leading research institutions, since the ITU-T/VCEG and ISO-IEC/MPEG two international standards organization proposed the next generation video coding standard. The main purpose of HEVC is to reduce 50% bit rate for equal perceptual video quality relative to the existing standard, and service for the HD/ultra HD and 3d video encoding. Comparing the existing standard, this article provides the overview of HEVC, introduces the new technologies and features about HEVC coding data structure, improvement and new technologies to the existing standard, and draws the conclusion about the key technologies and future research directions of HEVC at the end.