This paper reports the results of studies on biology of Large icefish introduced in Zaihe Reservoir during 1996-1997. The content includes feeding habit (component of food item frequeney and intersity of feeding), growth (relationship between body length and body weight, growth rate daily growth increment in otolith and growth), reproduction (sexual mature size davelopment of gonads fecundity sex ratio sexual cells spawning habit and embryonic development), population structure and behaviors. The feeding ch...