Abstract: The diet, age and growth of Hemimyzon sinensis in lower reaches of the Jinsha-jiang River were studied.The fish is omnivorous.It mainly feeds on algae, detritus of high plant, aquatic insect and mollusc.The proper materials for aging are scale and lapillus.The aging results from scale correspond with that from lapillus in 85 % .The back-calculated body length from scale fits the practical growth.The regression equation of body length with body weight is W= 1.08 ?10-4L2.5604, that of body length with radius of lapillus is BL=59.995 + 130R, and that of body length with radius of scale is BL= 36.704 + 117R.