This study was to investigate the algae preference of small abalone (Haliotis diversicolor) on the rearing plates. There were 22 genus in plates. Among them, 19 were diatoms and others were green algae (Choroomonas sp., Dilabifilum sp. and Ulvaria sp.) The distribution and composition of algae were different on the upper and lower parts of the plates. The dominant algae were Nitzschia sp., Synedra sp., Navicula sp., Diploneis sp., Cocconeis sp., Achnanthes sp. and Amphora sp. in order. By using one-way ANOVA and Kolmogorov-Smirnov test, the preference for ingested algae of post larvae were Navicula sp., Nitzschia sp., and Cylindrotheca sp. with significantly different (P<0.05). The feeding order was similar among 3, 7 and 20-days-old post larvae. However, Seminavis sp. in 3-days-old post larvae, and Melosira sp. in 20-days-old post larvae both were higher than that of other stages. These results suggested that the post larvae had preference to the benthic diatoms in various development stages.