Molting is an essential biological process for the growth and development of crustaceans, however, the molecular mechanism of molting on growth regulation is little known. In this study, molting and growth performance were individually observed under the indoor laboratory condition, and gene expression level of two molting-related genes (ecdysteroid receptor gene, EcR; retinoid X receptor, RXR), and one growth related gene (myostatin, MSTN) were investigated using quantitative RT-PCR method (Table 1 and Fig. 4). A total of 60 juvenile crabs in each male and female groups were reared in 120 water closets of 60 L with 1 individual in each closet for two molting times. The growth traits (body weight, carapace length, carapace width, and merus length of second foot) were measured for each crab at the initial stocking stage, on the fifth day after the first molting and the second day after the second molting. Meantime, muscle and hepatoparncreas tissues were immediately collected and stored in ﹣80℃ freezer after growth traits measurements at the second molting for further gene expression analysis. The correlation analysis was conducted between the expression level of the three genes (EcR, RXR and MSTN) and growth traits using SPSS software. A sharp gaining of body weight was found after molting, followed by a slow and continuous increment in post-molting stage (Fig. 1, 2). Condition factor that could be used as an index indicating the next molting was initiated when it accumulated over 60% (Fig. 3). There was no significant correlation between the conditional factor and morphological character (Table 2). Significant negative correlation was found between MSTN expression level and the growth rate of carapace length (r =﹣0.450, P < 0.05) and carapace width (r =﹣0.410, P < 0.05), but significantly positive correlation was detected between MSTN expression level and condition factor (r = 0.450, P < 0.05) (Table 3). There was no significant correlation between the EcR and RXR expression levels and the rate of weight increment, carapace length, and carapace width increment. Generally, higher expression of MSTN indicated lower rate of weight increment, and higher expression of EcR and RXR indicated higher rate of weight increment (Fig. 5, 6). This research indicates that a regular pattern on the growth performance, and condition factor measuring nutrient substance content could be used as an indicator showing the initiation of the next molting, and the gene expression of EcR, RXR, and MSTN are correlated with the growth traits in the juvenile Chinese Mitten Crab.