Abstract: In order to obtain the appropriate mature parents of Phascolosoma esculenta from the natural marine areas for large-scaled breeding,in the present study,the laying rules,fecundity and fertilization rate, and quality of oocytes of P.esculenta were studied under the condition of indoor artificial cultivations.The results showed that the average weight of P.esculenta parents was 4.61 g,and the male and female proportion of the natural population was uniform.The fecundity increased with growing weight,while the relative fecundity decreased when the individual weight reached a certain size(≥ 5 g).From June 30^th,2015 to September 22^th,2015,the period of parents spawning was 85 days and the total amount of eggs was 16.73 million.The amount of eggs was 7.495 million,6.995 million and 2.210 million in July,August and September,respectively,which was accounted for 44.8%,41.8% and 13.2% of the total amount,respectively.The quality of fertilized eggs from July to August was better than that in September.