In this study, growth data at different months of the fourth generation selective group and control group of pearl oyster Pinctada martensii were measured, and the correlation and regression analysis for shell length, shell height, shell width and body weight were conducted. The results showed that correlation coefficients among growth traits of selective group and control group at different months were extremely significant (P<0.01), and were 0.47-0.88 and 0.44-0.92 respectively. In addition to the fact that correlation coefficients between shell width and others traits of selective group at six months were greater than corresponding values of control group, correlation coefficients among growth traits of selective group were less than corresponding values of control group. The multiple regression equations estimated body weight of selective group and control group were significant (P<0.05), and coefficients of determination (R²) were 0.625-0.848 and 0.745-0.902 respectively. Coefficients of determination of selective group were all less than corresponding values of control group. The results of this paper provide theoretical guidance for determining the important target traits in selective breeding of Pinctada martensii.