Abstract: Cercariae of Schistosoma japonicum were transformed into schistosomula by syringe passage or fresh serum incubation. It was observed that the serum complement played a role in the transformation of cercariae to schistosomula.Observations on physiological and morphological changes of schistosomula were made 3 or 12 hours after they were transformed. Some important physiological changes in schistosomula including the evacuation of the content in preacetabular glands, water sensitivity and negative CHR were observed. In addition, transmission electron microscopy revealed that the glycocalyx was almost disappeared from the surface of schistosomula. The outer membrane was increased from trilaminate into heptalaminate. All these changes of artificial schistosomula correlated well to those by skin penetration. The artificial schistosomula could be used as materials for the study of their immunology and pharmacology.