His research interests include machine translation, dialogue systems, text mining, and also fundamental research on NLP. As a principal investigator he has been taking charge of more than 10 projects, including the Natural Science Foundation projects of China, the High-Tech. Program (“863”) projects of China, the project supported by the National Key Research and Development Program of China, and also some projects in international cooperation. He authored a book titled Statistical Natural Language Processing and co-authored a book titled Text Data Mining. Both the books are very popular and widely used in greater China. He is currently a member of International Committee on Computational Linguistics (ICCL) and the President of Asian Federation on Natural Language Processing (AFNLP). He was Chair of ACL-SIGHAN (2014 − 2015). Also, he is the vice president of the Society of Chinese Information Processing of China. He serves on the journals ACM Transactions on Asian and Low-Resource Language Information Processing (TALLIP) as Associate Editor, IEEE Intelligent Systems and Machine Translation as a member of editorial board, and also TACL as reviewer. He served many top-tier international conferences, such as COLING'2010 as organization committee co-chair, ACL-IJCNLP'2015 as PC co-chair, IJCAI'2017 and IJCAI-ECAI'2018 as area chair, AAAI'2019 and AAAI’2020 as area chair, and COLING’2020 as PC co-chair as well.