The rules of molting and growth of Portunus trituberculatus were observed in this study. The crabs were cultured in single individual basket at temperature 15.6℃-31.0℃, salinity of 19.0-30.2. During the growing douration, eleven molting phenomena were observed, the interval of molting increased with the growth. Meanwhile, the average body weight gradually increased from (12±1) mg to (205.23±25.69) g . The relative growth rate of body weight increased rapidly at the period of crablet (Ⅰ~Ⅳ), which ould reach up to 337.50% at the period Ⅳ, but maintained between 194.68% and 199.64% during the juvenile crab period (Ⅴ~Ⅶ) and decreased slowly after Ⅶ period. The correlations between carapace width (CW), body length (BL) and body weight (BW) in each period were exponential, W=1.18×10-4×L2.996 (R2= 1.000) was added to describe the correlation between CW (CW= L) and BW (BW=W). W=4.05×10-4×L2.998 (R2= 1.000) was added to describe the correlation between BL (BL= L) and BW (BW= W). Moreover, a function was established to infer the growth period from body weight with an accuracy of 91.76%. These results can provide some references for the biology studies

and culture of P .trituberculatus.