Abstract: The morphological taxonomy, geographic distribution and host specificity of Trichodina reticulata Hirschman & Partsch, 1955 were studied based on the freshwater trichodinid materials of recent ten years in China. The result indicates that Trichodina reticulata is one of the parasitic ciliates which are commonly found on the earth, with a concentrating distribution alongthe warm water areas between the south and north temperate zones. The morphological variation observed in different species of Trichodina reticulata exhibits a correlation between the host and the water temperature. In addition, Trichodina reticulata does not display any specificity to its host and parasitic locality.