Abstract: This paper presents a comprehensive survey on the recent development of realistic 3D facial expression synthesis.Based on the key techniques adopted,we classify facial expression synthesis methods into five categories:shape interpolation facial expression synthesis,direct expression transfer,sketch-based facial expression synthesis and editing,machine learning based realistic facial expression synthesis,the extraction and synthesis of high resolution facial expression and details.We first give the research status of each category,and then address the strength and weakness.Conclusions and future trends for facial expression synthesis are also presented.