He has worked on a number of topics related to Web search and data mining, including query representation and understanding, learning to rank, and topic modeling. His current research is focused on representation learning and deep models for information retrieval and information filtering. He has published more than 80 papers in international journals and conferences, including IEEE TKDE, Information Retrieval Journal, Journal of Statistical Mechanics, SIGIR, WWW, CIKM, ICDM, WSDM, and IJCAI. He has won the Best Paper Award in ACM CIKM (2011) and Best Student Paper Award in ACM SIGIR (2012).