Abstract:A 42-day feeding trial was conducted to investigate the effects of dietary phospholipids on the choline requirement of the juvenile Chinese mitten crab, . Twelve purified diets were formulated containing two phospholipid levels (1% and 2%) and six choline chloride levels (0, 250, 500, 1 000, 2 000 and 4 000 mg/kg diet), and were fed to juveniles (0.22g±0.01g) with four replicates in each treatment. The results showed that dietary choline and phospholipids had a significant interaction on survival, weight gain, specific growth rate and feed conversion ratio (<0.05). Crabs fed diets with 1000 mg/kg dietary choline chloride (1% phospholipids) and 500 mg/kg choline chloride (2% phospholipids) obtained the highest survival rate, and significantly differed from that of other treatments with low choline chloride (<0.05). Crab weight gain and specific growth rate significantly increased with dietary choline levels from 500 to 4000 mg/kg (<0.05). Feed conversion ratio decreased significantly with dietary choline chloride increasing from 1 000 to 4 000 mg/kg (<0.05) at the 1% phospholipid level. At the 2% phospholipid level, feed conversion ratios of crabs fed diets with 500 and 1000 mg/kg choline chloride were significantly lower than those of the 0 mg/kg group (<0.05), but no significant differences were detected among the 250, 2 000 and 4 000 mg/kg groups. Whole body crude lipid hepatopancreas triglycerides, hepatopancreas total cholesterol, hepatopancreas glutamate pyruvate transaminase and glutamate aspartate transaminase activities significantly decreased with choline chloride increase, regardless of the phospholipid level (<0.05). Broken-line regression analysis based on weight gain against dietary choline levels indicated that the optimal dietary choline requirements of juvenile were 1 429.65 mg/kg and 529.65 mg/kg at the 1% and 2% phospholipid levels, respectively.