This paper deals with the biological characteristics of white cruclan carp (Carassius auratus cuvieri，which includs (1) Sixxdies on its morphologic al characteristics, living habit, reproduction feature, feeding habit and embrpvn.ic development;(2) Experiments on its growth speed, catching rate and disease，(3) Bear surement of fattiness, nutritional composition and the content of amino acid in muscle;(4) Anal州。of chromosome and serum. protein electrophoresis. Besides, the compari- son between different variety of crucian carp is also made. The seg ratio of C. auratus cuvieri is 1:I，which is different from that of C. auratus gibelio or C. auratus,a local variety. C. auratus cuvierihas more gill rakes ( the maximum can be 12o rakes ) which are long and dense, and of same length with the bronchial filament. The lateral swelling of the gill rake is both Iang and branched. The intestines of the adult fish is thin and twisted，the length of which is 5.6 times of the body length. The intestines wall is also thin.The fish has a wide feeding habit,belonging to omxiivaroue 印ecies which. feed on phytoplanlitans too.Both C. auratus cuvieri and C. auratus gibelio have the same chromosome, being 2n=100. C. auratus cuvieri grower 12-46 .2% faster than. C. auratusand its catchzng rate is as high as over 90%，much higher than that of C. auratus gibelio (50%)or C. auratus (5%). Its fattiness is 3.07--3.24, and as the empty weight of tho fish accounts for 85-86% the total body weight, this variety of crucian carp has a better economic value. The contents of protein and fat in muscle of C. auratus cuvieri are similar to those of C. auratus gibelio or C. auratus, but its Water content is a little higher. The contents of histidine, arginine, glutsmic said, alanine, leucine etc. of C. auratus cuvieri are atso a little higher than those of the other two varieties. In general, C. auratus cuvieri has a fester growth rate and a wide feeding habit.Its population yield is also high, so the fish has a better economic efficiency and is an excellent variety for warm water fish culture.