Experiments for rearing silver carp fingerlings in cages by feeding an natural food, have been carried out successively far three years in the Bailianhe Roservoir.The present paper is based upon the work from June 18 to august 28 in 1978. The fingerlings were raised in rectangle cages of 7 x 3 .5 x 2 M with the volume of 40.38 M³. Fingerlings of 3.95 cnz in average length were stocked in 14 cages with different densities of 2.13-1.211 ind./M^a in number. 1Lt the end of the experment、totsl amount of 243,759 fingerlings were harvested，the fish grew about 12.23-16 .95 cm in length and the average ptoduction was 277ind./m³. The object of the experiment was to study the effects of stocking densities on grow th，survival and production in order to determine the optimum cage-rearing density for sih'er carp fingerling in the Bailianhe Reservoir.