Abstract: Matings and crosses within and among geographically dif ferent populations of Pinctada martensii (Dunker) were carried out in order to breed new strains for pearl culture. Six populations of the f irst filial generation have been obtained. Three populations, designated BB1, DD1 and SS1, were from matings of wild populations of Beihai( BW) , Daya Bay (DW) , and Sanya ( SW) . Three populations, that is BD1, BS1 and DS1 were from cross between BW and DW, BW and SW, and DW and SW respectively. After analyzing f ive trait s, shell length, shell width, shell thickness, total weight and shell weight by ANOVA, no population of first generation from crosses had heterosis in growth. Six populat ions gained were considered as the basic populations to breed new strains. Increased Variation parameters in first f ilial generation( F1) of cross could be a very good potential for selecting new strains.