The fish resources in Heilongjiang Xingkai Lake National Nature Reserve were surveyed from May 2009 to January 2012. Total of 67 species were accumulatively recorded, 60 of them were indigenous. The realm of fish in Xingkai Lake is formed by 55% palaeoarctic realm species, and 45% oriental realm species, fish species belonged to Cypriniformes was the largest fish group. Most individual of fish harvested was smaller at age of 1-2 in the duration of 2009 to 2011. Over exploration on the fish resource is the main problem in the reserve.