Abstract: Small abalone Haliotis diversicolor is an important cultivable species in Southern China. A new variety, Dongyou No.1, is now widely cultured because of its high survival rate. We conducted a 3×3 complete diallel cross between three populations of small abalone H.diversicolor, which were Dongyou No.1, Gulei and Vietnam. During the crossbreeding, we compared the six reciprocal cross lines and three parental lines in terms of growth rate and survival rate at grow-out stage, and analyzed their heterosis. Significant difference in shell length and survival rate had been found, which indicated a potential genetic difference between the three populations(P < 0.05). The magnitudes of heterosis was not high, and differed within the cross lines, for both positive and negative values could be observed. Moreover, the two single-parent heterosis were significantly different from each other (P < 0.05).