Due to the high meat yield and rich nutritional content, jade perch () has become an important commercial aquaculture species in China. Jade perch has a slow growth rate, taking 3-4 years to reach sexual maturity, and has almost no difference in body size between males and females. However, the study of its gonad development and reproduction regulation is still blank, which limited the yield increase. Herein, the gonad transcriptomes of juvenile males and females of were identified for the first time. A total of 107,060 unigenes were successfully annotated. By comparing male and female gonad transcriptomes, a total of 23,849 differentially expressed genes (DEGs) were identified, of which 9517 were downregulated, and 14,332 were upregulated in the testis. In addition, a large number of DEGs involved in sex differentiation, gonadal development and differentiation and gametogenesis were identified, and the differential expression patterns of some genes were further verified using real-time fluorescence quantitative PCR. The results of this study will provide a valuable resource for further studies on sex determination and gonadal development of .