In order to understand and utilize heterosis and select the perfect one of numerous combination by multiple crosses,the present study attempts to analyse the utilization of heterosis by building the regression model,variance components,grey correlated degree,and comparing the prediction results through different methods based on the phenotype analysis of growth traits of 3?3 full diallel cross of common carp(Cyprinus carpio)(Jian carp,Huanghe carp and Heilongjiang carp).The results showed that:(1) The two formulas of functions were different by considering the tagging traits or not.Body length and tagging length had significant influence on body weight by creating multiple stepwise regression model together with grey correlated degree analysis;(2) Significant fixed effects of combination,combination(family)and initial weight(iw)?dam were observed;(3) combination Hyj,Hjy and JJh should be considered first in the compound breeding program.This illustrated that fixed effects of initial weight(iw)?dam,tagging length should be considered.The results also showed that utilization of heterosis can be increased by multiple crosses.