Abstract: The articles regarding to the ecological study on the planktonic and periphytic pro-tozoans in lake Dong Hu were published in 1965 and 1980 respectively. The presentpaper deals with the descriptions of six new species of periphytic protozoa in thesame lake during the period from December, 1963 to December, 1964. In the previouspublication (1980) there contained a list of 175 species of periphytic protozoa, amongthem 66 species belong to new records in China. The diagnostic features of the 6 newciliates are given below: 1. Epistylis chlorelligerum sp. nov. Length of zooid: 160-250μ; width of zooid: 45-83μ; diameter of peristome: 57-78μ; width of ciliated disc: 37-53μ; width of pedicle: 15-20μ; length of colony:1.5-2 mm. Body barrel-shaped, width one fourth the body length. Ciliary wreath in two con-volutions rolled into the vestibulum. Ciliated disc considerably elevated. Peristomalborder compacted and swollen, distinctly constricted below the peristomal border.Cuticular surface obvious, striated transversely. Macronucleus horizontally located.Endoplasm containing numerous zoochlorellae which distinguish this species from otherrepresentatives of the genus. Found from lake Dung-hu, more abundantly in summer andautumn. 2. Vaginicola cupulata sp. nov. Length of lorica: 40μ; diameter of aperture: 50μ; length of zooid: 150-170μ. Lorica cup-shaped, its posterior end greatly attenuated into a small spherical baseattaching to the substratum. Yellowish in colour. Aperture broad, with rim. Wall oflorica with 8 circular bands. When extended the zooid protrudes three fourths length ofthe body out of the lorica. The present new species differs from the allied species byits cup-shaped lorica together with several circular bands. 3. Vaginicola curvata sp. nov. Length of lorica: 166μ; width of lorica: 43μ; length of zooid: 186μ; width ofzooid: 20μ; diameter of peristome: 34μ. Lorica transparent, its anterior two thirds straight cyclindrical and its pos-terior one third attenuated bluntly conical. At the junction of the two parts,lorica bent at angle of 120 degrees. Usually two zooids enclosed in a lorica. In extend-ing state only one fifth length of body protrudes out from lorica. Cilliated disc slightlyelevated. Macronucleus band-like, but rather shorter than other species, slightly bent atboth ends. This new species resembles V. inclinata, but distinctly differs from the latter by having the lorica bent with an angle of 120 degrees. 4. Vaginicola plicata sp. nov. Length of lorica: 120-150μ; width of lorica: 35-42μ; length of zooid: 150-185μ. Lorica cylindrical, its anterior end pitcher-shaped, extended outwards; posteriorend distinctly plicated and extended into fan-shaped at the base, with which attached tothe substratum. Length about 2.5-3.5 width of the lorica. Brownish in colour. Zooidabout one fourth length of the body extending out of the lorica. Surface of cuticulafaintly striated transversely. Macronucleus band-like, slightly twisted. This new speciesdiffers from the allied species of Vaginicola tincta and V. ceratophylli by having theplicated contour at the posterior end of the lorica. 5. Cothurnia magna sp. nov. Length of lorica: 200μ; width of lorica: 56μ; length of pedicle: 95μ; width ofpedicle: 3μ; length of zooid: 280-300μ; diameter of peristome: 52μ. Lorica transparent, elongated cylindrical; posterior end conically tapered about atone fourth of the total length. Pedicle nearly a half length of lorica. In extendingstate zooid extended one third of the body length out of the lorica, and fixed to thebottom of the lorica by a very short thin stalk separated from the pedicle. The animalis characterized by its exceedingly large size. 6. Platycola multistriata sp. nov. Length of lorica: 85-90μ; width of lorica: 60-64μ; width of aperture: 36-45μ; high of aperture: 16-27μ; length of zooid: 130-140μ; width of zooid: 20-23μ; diameter of peristome: 26μ. Lorica ellipsoidal, but slightly straight at both lateral sides. Surface of lorica dis-tinctly annulated with 13 rows of transverse striations with equal intervals. Apertureof lorica ellipsoid, its rim uniformly notched. Lorica yellowish-to reddish-brown incolour, become darker with age. Usually two individuals enclosed in one lorica and ex-tended to a half length of body out the lorica. Cuticular surface distinctly striated,transversally. Ciliated dise exceedlingly elevated. This new species may be easily recog-nized by the presence of 13 rows of transverse striations on lorica and the peculiar formof its aperture. Sporadic species.