Abstract: Gift strains of Nile tilapia (Oreochromis niloticus) have become the main aquaculture fish in China′s tilapia industry. We constructed nine complete set combinations through 3×3 complete diallel cross among three strains of Gift Nile tilapia (New GIFT, GIFT and Genomar) to analyze the combining ability, heterosis and genetic correlation in F₁ progenies among these nine combinations for five growth traits (body weight, total length, body length, body height and body width). No general combining ability was detected for the five growth traits, while the special combining ability was over 62%, which indicates that the growth traits were mainly affected by special combining ability. Significant heterosis was observed in the three combinations of Genomar♀×New GIFT♂, New GIFT♀×Genomar♂ and GIFT♀×New GIFT♂, among which Genomar♀×New GIFT♂ was the best complete set combination. Besides, significant genetic and phenotypic correlations were detected among the five growth traits (P < 0.05), indicating polymerization utilization could be conducted in multiple traits in the future. Thus, the results provide references for complete set utilization and breeding of GIFT tilapia.