Abstract: Morphogenesis of the marine ciliate,Euplotes charon was investigeted with protargol impregnation method.The results demonstrate that the main events of the cortical pattern during the morphogenetic procedure are very similar to those of other known Euplotes species.The general procedure is:1) along with the reorgnization of the macronucleus,the opisthes oral primordium appears de novo under the pellicle posterior to the buccal field,from which the AZM,PM and one of frontal cirrus will be derived;2) two groups of FVT cirral anlagen each with 5 streaks occur de novo,which will be differentiated separately to the frontoventral and transverse cirri in both dividing parts.Different from that of most other hypotrichs,the process of development of the anlagen according to an order from left to right;3) anlagen of dorsal kineties appear within the old structure,where the caudal cirri come from the right-most two anlagen.All the morphogenetic characteristics mentioned here or those described previously by other authors have agreed with the systematic arrangement that euplotids with related genera might be devided into several independent taxa within the order Hypotrichida.