Although pond culture is the major culture method for swimming crab Portunus trituberculatus, the growth and gonadal development pattern of pond-reared males remain unclear. Firstly, this study was conducted to investigate the changes of the growth parameters, the overall appearance and composition of mature reproductive system of male P. trituberculatus. Then, the changes in testis and vas deferens histology, gonadosomatic index, testis index, vas deferens index, hepatosomatic index and the gonadal development pattern during the process of pond culture were described. The results showed that: (1) The highest growth rate and specific growth rate of body weight and carapace width of male P. trituberculatus were found during the period of July to August (Fig. 2, 3). Furthermore, a significantly positive correlation was found between body weight and carapace width for pond-reared male P. trituberculatus (Fig. 4). (2) The mature reproductive system of male P. trituberculatus consisted of external and internal parts: the external part included the penis and petasma consists, while the internal part mainly included testis and vas deferens (Fig. 5). (3) Based on the changes of morphology, histology, and indices of testis and vas deferens, the gonadal development process of P. trituberculatus could be divided into three stages. Spermatogenesis (stage Ⅰ): the dominant types of gametocytes in testis were spermatogonia and primary spermatocytes, the testis index of stage Ⅰ ranged from 0.07 to 0.16, and the vas deferens appeared transparent and was hard to be found (Fig. 6, 7). Spermatophore formation (stage Ⅱ): secondary spermatocytes and spermatids were the dominant types of gametocytes in testis (Fig. 6, 7), and the testis index of stage Ⅱ ranged from 0.10 to 0.51. The vas deferens was filled with a large amount of fluid and spermatophores, and the vas deferens index of stage Ⅱ ranged from 0.01 to 0.41. Mature stage (stage Ⅲ): the gametocytes in testis were mainly composed of spermatids and spermatozoa (Fig. 6, 7), and the testis index of stage Ⅲ ranged from 0.10 to 0.41. The vas deferens was further enlarged and the vas deferens index of stage Ⅲ ranged from 0.20 to 0.65. (4) During the gonadal maturation, the gonadosomatic index and vas deferens index increased significantly, while the testis index showed a trend of increasing first and then decreasing (Fig. 8, 9). Furthermore, there was no significant correlation between gonadosomatic index and hepatosomatic index. (5) The gonadal development of pond-reared male P. trituberculatus was not synchronous. In July, the gonadal development of pond-reared male P. trituberculatus was mainly in stage Ⅰ (Fig. 11). At the end of August, the percentage of males reached stage Ⅱ was 76% (Fig. 11). At the end of September, the percentage of males reached stage Ⅲ was 47% (Fig. 11). From mid-late October to December, the gonadal development of pond-reared male P. trituberculatus was mainly in stage Ⅲ (Fig. 11).