Abstract: The present paper deals with the morphology of matured eggs and sperms,the surface structure and morphology of the chorion of eggs,the site and structure of micropyle,and the process of fertilization in Clarias lazera by SEM.The spermatozoon retains a primitive type,divided into head,middle and tail.The Chorion contains zona radiate and attachment disc.Attachment disc is only at the top of the egg.There is a single micropyle in the center of attachment disc.Only one sperm can pass it at a time.After fertilization,the micropyle appeared some secretion.The secretion sticks with the sperms that cant enter eggs to form mass which limited other sperms go into the egg.The process of fertilization is about 60 seconds.In this paper,the process of sperm enters into the egg of fish and a material of fertilizin was supposed to exit.The fertilizin in the micropyle,which may be from the dissolved micropylar cell,probably has function as attracting sperms.Besides,other questions were discussed.