Abstract: Lake Xingkai（Khanka） and lake Mini-xingkai locate in the northeast boundary of China,are just separated by a natural mound.Large ice fish（Protosalanx hyalocraniu） was introduced into lake Mini-xingkai to increase the fish yield unsuccessfully,however,it developed its population very well after getting into Lake Xiangkai with the flood from lake Mini-xingkai.Fish composition of Lake xingkai and lake Mini-xingkai was investigated from January through December in 2010 to find out the relationship between Large ice fish population development and the differences of fish community.The investigation results in 56 species of fish including 3 new record（i.e.chum salmon Oncorhynchus ketaPike,perch Lucioperca lucioperca and Misgurnus moloity（Dybowski）,Misgurnus moloity（Dybowski））in lake Xingkai,and 33 species of fish including 3 new records（i.e.fat minnow Sarcocheilichthys lacustris,northern sheatfish Silurus soldatovi and Large ice fish）,meaning sharp reduce of 10 species in the past 15 years in lake Mini-xingkai.There is still relatively high similarity in species composition between the two lakes with Sorenson index of 0.72 while the biomass composition was significantly different resulted from the different environmental characteristics.As a large lake located in subfrigid zone,Lake xingkai has its own special hydrological and ecological characteristics,indicated in less biomass of fish that prefer living in macrophyte lakes.The contribution of fish community differences of lake Xingkai from lake Mini-xingkai to Large ice fish population growth was discussed in this paper.

Key words: Lake Xingkai（Khanka）, lake Mini-xingkai, fish composition, exotic fish