Abstract: This paper is the first report on the ultrastructure of daughter redia of Paragonimus westermani in China. The specimens were obtained from naturally infected Semisulco-spira libertina collected from Daye, Hubei Province.The daughter redia of P. westermani is elongated or in the shape of slightly bent cylinder. The outer surface of tegument is folded in the form of annular ridges and troughs. The body surface is frequently contoured to show the outline of developing cercariae inside. At the anterior end, the daughter redia looks conical. The mouth is at the tip of the anterior end and surrounded by a thinner ring of tegument forming a distinct lip. A short distance behind the mouth there was a "birth pore" which is sur-rounded by microvillous projections, vesicles and pits.On the surface of the daughter redia, many microvillous projections are observed and numerous tiny vesicles are attached to the tegument, thus greatly increasing the absor-ption surface area of the tegument and serving in the transport of nutrients through the microvillous projections from the outer surface into the tegument.