In order to investigate growth and morphological differences among Larimichthys polyactis, L. crocea and their hybrids (L. polyactis ♀ × L. crocea ♂), the body weight of the three kinds of fish were compared in 3, 4, 6, 8, 11, and 15 month of age, and the phenotypic traits (total length, body length, head length, trunk length, tail length, caudal peduncle length, caudal peduncle depth, body depth, body weight, and condition factor) variations of 8 month of age L. polyactis, L. crocea and the hybrids were measured and analyzed. The results showed that the body weight of L. polyactis was significantly higher than that of L. crocea and the hybrids before 4 month. From 4 month of age, body weight of the hybrids greater than that of L. polyactis, and L. crocea, but the body weight of L. crocea higher than the hybrids at 15 month of age since the growth rate of L. crocea increased obviously from 11 month of age. Thus, at last, the body weight of the hybrids was between in those of the parents, which means the hybrid showed a mid-parent heterosis. In the results of morphological differences analysis, there were significant differences in phenotypic traits among L. polyactis, L. crocea and hybrids (P<0.05). In which, both the body weight and condition factor of the hybrids were significantly higher than the two parental groups (P<0.05). A cluster analysis revealed that the difference between hybrids and female parents is less than the difference between that and male parents, suggested the hybrids resemble female parents in morphological traits. A discriminant analysis for the morphological traits of the three groups was carried out, and three discriminant functions were established for the three groups, and resulting in a comprehensive discriminant rate of 80.6%. In which, the discriminatory accuracy of L. crocea was as high as 94.6%, which was higher than those of the L. polyactis (73.5%) and hybrids (74.6%), suggested again that the hybrids has a significant maternal effect on morphological traits. The purpose of this study is to provide theoretical basis for the morphological and phylogenetic identification and hybridization selection of L. polyactis, L. crocea and hybrids. The study would be beneficial for identifying groups, and for determining genetic relationships and breeding.