Heng Guo graduated with a B.S. in mathematics and M.S. in computer science from Peking University. He is currently a Ph.D. student in computer science at the University of Wisconsin-Madison. His research area is the study of complexity of counting problems, in particular dichotomy theorems which classify all problems in a class to be either polynomial-time computable or #P-hard. Extended abstracts of his papers have been published in the proceedings of conferences such as ICALP, STACS and STOC. His joint paper with Pinyan Lu and Leslie Valiant proved a complexity dichotomy theorem for all parity Holant problems with arbitrary symmetric constraint function sets. Holant problems are a refined framework from CSP for counting problems and are motivated by holographic algorithms. His joint paper with Jin-Yi Cai and Tyson Williams proved a complexity dichotomy theorem in the same setting for all complex-valued Holant problems. This is the culmination of a long series of previous work.