In this study, we analyzed the correlation of 20 growth-related traits and their effects on body weight of Scylla paramamosain. The correlation coefficients in all trait pairs were significantly high, ranging from 0.551 to 0.999. Among 19 X-Y pairs, the correlation coefficient between traits X1 and Y was the highest, whereas that between X13 and Y was the lowest. Path analysis indicated that only two traits (X1 and X14) can significantly affect body weight (Y) directly, with the path coefficients being 0.800 and 0.198, respectively. The determination coefficients (di) of traits X1 and X14 to body weight were 0.640 and 0.039, respectively, and the total di was 0.965, indicating that both traits were the key factors affecting body weight. Moreover, traits X1 and X14 were confirmed to be significantly related to body weight. Finally, a best-fit linear regression equation was constructed as Y = 4.192X1 + 2.242X14 - 169.737.