Abstract: Through observing the regenerative process on the fragments of excised Tachysoma pellionella,it is considered that the macronucleus of the animal plays an important role to its regeneration,and the morphogenesis of infraciliature in fragments is related to their corresponding.This is coincide with the results of many studies of other protozoologists.Further,it was observed that:(1)The old adoral zone of membranelles (AZM) exercises some inhibitory effects to the differentiation and shifting of cirri on new cirri promordia in the regenerating fragment.(2)These effects are weaker in the distal parts and stronger in the proximal parts.(3)These inhibitory effects disappear with the disintegration and absorption of the membranelles of old AZM,as well as the completion of regeneration and fenewing process of new AZM.