The clam (Ruditapes philippinarum) was produced by artificialinduced breading and cultivated in laboratory for the study of its life history Its mor-phological changes at various development stages from fertilized egg to spat (with 7mm, shell length) were observed as well as the yearly change of the spat in naturalsea area. It was further confirmed by observing the morphological characteristics ofspermatizoa and spat that the correction of Ruditapes variegata (Sowerby) which wasmainly cultivated in Fujian province to be Ruditapes philippinarum (Adams Reeve) was valid.