The embryonic and larval developments of the prosobranch gastropod mollusk Neverita didyma were observed under laboratory conditions with artificially hatched from egg masses.Early development of N.didyma belong to indirect developmental type.Embryonic development stages include cleavage,blastula,gastrulae,trochophore,and intra-membrane veliger.Larval development stages include veliger,late veliger and groveling larva.Groveling larvae metamorphosed to juvenile.The fertilized egg developed to intra-membrane veliger in about 38 hours and hatched in 5 to 6 days after veligers at temperature 25-26℃.Morphological characteristics of N.didyma veliger can be concluded as:there are a pair of eyes,a pair of statoliths and bi-lobed velum;the velum of late veliger is four-lobed as butterfly,the foot showing broadened;larvae can free-swimming and creeping;late veligers get more growth and gradually become groveling juveniles.