This paper presents the experimental results of feeding mussel larva with Phaeodactylum tricornutum, Chaetoceros muelleri,Platymonas subcordiformis, Nannochloris oculata, Dicrateria zhanjiangensis, live beer yeast, medicine yeast tablets and soy-bean powder. The triradiate form of Phaecodactylum can be used by early stage larvae, which can grow evenly in size and has higher survival rate. Fusiform Phaeodactylum cells are not so good as feed as the triradiate forms, but they have the advantage over the former of being able to tolerate higher temperature thus can serve as food for a longer duration. Minute fusiform Phaeodactylum, just 9一16μm in length, is a good food for early stage Larva. Chaetoceros muelleri can be used by young larva as well. The effect resulting from giving such a feed is similar to that of giving Phaeodactylum ,but it requires higher culture temperature. This algae can be used as an early food in autumn spat-rearing. Platymonas is only suitable for larger larva due ,to its bigger cell. It can not be used until -the shell-length of ,the larva attains 120μm and it is most effective as feed when the temperature ,of the water is above 15°C. Nannochloris oculata, although can be easily swallowed by mussel larvae, is not an effective. feed as it hardly promotes the larvae's growth. Dicrateria zhanjiangensis is an effective food, though not so good as Phaeodactylum. Soy-bean powder, although better than beer yeast and medicinal yeast in food value, is not so good as Phaeodactylum. Soy bean powder and yeast, which are readily available and easy to keep, can be resorted to whenever there is an insufficient supply of the better feeds.