Growth and survival (%) of the larvae and spats of Scapharca broughtonii fed on three different microalgal species (Isochrysis galbana, Pavlova lutheri and Chaetoceros simplex) were investigated with the analysis of fatty acid composition. The larvae fed on mixed diet with three microalgal species showed the highest growth in shell length (261.3 ± 13.5 μm) and survival (27.4 ± 5.3%). The growth and survival (%) of the larvae fed on the single diet with C. simplex were significantly higher than those of the larvae fed on I. galbana or P. lutheri (P < 0.05). The growth and survival (%) of S. broughtonii spats reared for 30 days were also highest in the mixed diet group with 1,114.8 ± 128.0 μm and 61.3 ± 5.5%, respectively, and followed by C. simplex, I. galbana and P. lutheri. With respect to composition of fatty acid of the single or mixed microalgal diet, the content of PUFA and n-3 HUFA were the highest in C. simplex. This result can be considered as the reason for high growth and survival (%) of the larvae and the spats. C. simplex was the best species as the single diet, but the mixed diet with three microalgal species showed better dietary value than single diet did for the larvae and spat of S. broughtonii.