Abstract: Tilapia is one of the major fish species cultured in the world; genetic improvement of tilapia is very important. Growth performance of GIFT strain of Nile tilapia Oreochromis niloticus was checked by communal testing in concrete ponds. F₆, F₇ and F₈ were compared from seedling in 2004. The averages of daily body weight gain of F₆, F₇ and F₈ were 1.07, 1.12 and 1.47 g · d^-1, respectively, after raised for 114 days. After correcting the bias (which may caused by the weight because F₈ was bigger in weight than F₇ and F₆ at the beginning), the body weight gain rate of F₆, F₇ and F₈ was 1.13, 1.18 and 1.36 g · d^-1, respectively. Variation coefficient of body weight of F₈ was lower than F₇ by 6.29%, and lower than F₆ by 7.95%. Growth equation of F₈ was: y=40.313x－61.670 (R²=0.8783, R=0.9513).