The present paper describes the morphology, infraciliature, siliverline system and the morphogenesis of Chilodonella cyprini. There are two circumoral ciliary rows and a preoral ciliary row on the buccal region and a dorsal row of bristles. The number of the ciliary rows on the ventral surface varies rather widely. In the light of the development of its infraciliature and nuclei, 7 morphogenetic stages are described. The left lateral system of ciliary rows has divided at the same time while the right ciliary rows are not changed. A short basal granular row forms the dorsal row of bristles of the opisthe. The proter reserves the frontal part of the old oral basket and the oral basket of the opisthe forms newly. Based on the results, some morphological characteristics, the mechanism of the oral basket's formation and its taxonomy are discussed.
