Abstract: In the development of tilapia industry, excellent quality of tilapia fry is a key point to guarantee the rapid growth rate and good economical benefits of marketable fish. At present, the domestic fry market is increasing rapidly, but the tilapia fry are on various levels of quality. The hybrids of Oreochromis niloticus♀ × O. aureus♂ are one of the most popular commercial types for tilapia farmers, because of rapid growth rate, strong resistance to disease and low temperature for the hybrids. But due to complex origin of the fry parents, the hybrid effects and the cultured benefits are being reduced greatly. Therefore choosing superior hybrid combination of different parental strains is essential. In order to understand and utilize heterosis and select the perfect hybrid subgroups of combinations, differences of growth characters among numerous subgroups should be objectively evaluated. In our research, two strains of Oreochromis niloticus (XX, EE strain) and two strains of O. aureus (ZZ, AA strain) and their hybrid subgroups of Oreochromis niloticus♀ × O. aureus♂(XZ, EZ, ZA, XA) were produced and injected with RFID electronic tags to track and measure growth characteristics for comparative analysis. All the tilapia parents came from technology research center of national tilapia industrial system, which was one of the most important tilapia breeding bases in China. All the fry of combinations except ZZ strain had been hatched out, fifty individuals of each combination were picked out for our analysis. All the individuals for analysis were cultivated in the same pond and fed twice daily, the air pump had been installed in the pond. The results showed that the male ratios of XZ, XA, EZ, EA subgroups were 96.0%, 94.0%, 98.0%, 95.7%, while the ratios of XX, EE, AA strains are 58.0%, 66.0%, 52.0%, respectively. After 380 days of cultivation, at least four morphological characteristics such as total length, standard length, head length and body depth of four hybrid subgroups were significantly more than those of their parental strains (P0.05), while there were more advantages of growth rate in hybrid tilapia subgroups than parental strains. Meanwhile, there was significant difference (P0.05) in growth characteristics among the four hybrid subgroups. Significant correlations were existed in body weight and other morphological characteristics, the correlation coefficients between body weight and caudal peduncle length (0.690-0.846) were obviously lower than that between body weight and total length, standard length, body depth and body width. Data on body weight and morphological characteristics were used for principal component analysis, the characteristics including body weight, total length, head length, body depth, caudal peduncle length, caudal peduncle depth and body width were divided by standard length. In order to eliminate the influence of differences in body size among the tilapia individuals, we obtained seven proportion characteristics including BS, TS, HS, BDS, CLS, CDS and BWS respectively. In the characteristic coefficients plots of principal components factor scores, those seven proportion characteristics were divided into two groups, the first group concluded BS, BDS, CDS and BWS, the other concluded TS, HS and CLS. We draw a scatter plot through the score coefficients of tilapia individuals in principal component factors PCR1 and PCR2. In the plot the individuals of AA strain could obviously differentiated from other subgroups.