Abstract: Outdoor experiments were conducted to investigate the sea cucumber (Apostichopus japonicas Selenka) in earthen ponds.Four kinds of shelter (scallops cage,woven bags,sunshade nets and hollow brick) and the changes of species composition,density and biomass of benthic microalgae were analyzed,while the effects of four kinds of shelter on growth and survival of sea cucumber were also studied.The results indicated that the abundance and distribution of diatoms determined the total variation of the benthic microalgae abundance.The average value of benthic microalgal biomass were 3.46,2.46,2.77 and 3.82 μg.cm^-2,respectively.There were significant differences of sea cucumber's growth and survival rate among the four kinds of shelter.The growth of sea cucumber on hollow brick was the slowest,but the survival rate (66.5%) and the yield (192.8 g·m^-2) were the highest.The survival rate of sea cucumber on scallop cage was 48.7%,and the yield of it was 169.8 g·m^-2,which were only next to hollow brick.The survival rate and yield of sea cucumber on woven bag or sunshade net were low.The results showed that the survival rate and the yield of juvenile sea cucumber in earthen ponds was closely related to the biomass of benthic microalgae on the shelter.