Abstract: In order to investigate the effects of 2 diatoms on the growth or survival of larvae and juveniles of Haliotis diversicolor, we compared Pinnularia sp.,Amprhora exigua and the mix (a mixture of Pinnularia sp. and A. exigua) with the control (natural diatoms collected from sea). The results indicate that different diets have significant effects on the growth and survival of H.diversicolor of different sizes (P0.05).There is no significant diffrence in the growth and survival of larvae fed with Pinnularia sp., A.exigua and the mix (P0.05), and all significantly lower than that of the control (P0.05). No significant difference is found in the growth and survival of the juveniles fed with A.exigua,the mix and the control, but those fed with Pinnularia sp. have significantly lower growth and survival than the control.