The present paper deals with 19 species of Myxosporidia which were collected from731 individuals belonging to 9 species of freshwater fishes in Weishan-Chaoyang andNanyang Lakes. Among these parasites, 16 species are previously known, namely: My-xidium enchelypteryii, M. orientalis, Myxosoma acuta, Myxobolus dispar, M. derma-tobius, M. cyprini, M. sqamocus, M. ellipsoides, M. migairii M. exiguus, M. gigi, M.koi, M.toyamai, Thelohanellus fuhrmanni, Henneguya sinensis, and H. doneci. Theremaining three are new species and their diagnoses are summarized as follows: 1, Myxosoma carassii sp. nov. (Figs. 9-11). On the gills of Carassius auratus(L.). The fresh spherical cysts are 0.80-0. 12 millimeters in diameter. In front view,the spore is pyriform with a somewhat hent anterior end, but it is nearly fusiform insutural view. Certain species have a thin envelope around the posterior end. The ante-rior end of the envelope expands into a cup-like structure which fits closely the pos-terior part of the spore. Its external measurements are 5. 62 (4.50-6.50) 10. 60 (9. 50-11.50)μ. The shell-valves are moderately thick and the sutural ridge is straight anddistinct. The two equal polar capsules are clongated pyriform and its coiled filamentis distinct. A small intercapsular projection is present. Dimensions of the fresh spores:leugth 15. 43 (12.50-17.50), width 10 .42 (8.75-12. 50)μ., thickness 7.94 (7.50-8.75)μ.; polar capsule 8. 30 (6.25-8.75) by 3.58 (3.12-3. 75)μ. 2, Myxobolus shantungensis sp. nov. (Figs. 25-29). On the gill rakers of Cyprinuscarpio L. The fresh cysts are spherical nodules, and surrounded by a thick layer ofconnective tissue. They are 3-9 millimelers in diameter. The spores are nearly trans-elliptical in front view and fusiform in sutural view. The shell-valves are comparativelythick at the posterior end and the sutural ridge is straight and distinct. Six to seven"V"-shaped markings are observable along the posterior half of the shell. The two eq-ual polar capsules are large and pyriform, but the polar filament is inditinct in bothfresh and stained materials. A small intercapsular projection is distinct. The sporoplasmcontains a smaller iodophilic vacuole and two nuclci. The two kidney-shaped capsulo-genous nuclei are distinct, Dimensious of the fresh spores: length 8.12 (7.50-8.75)μ, width 9.90 (9.37-10.00)μ, thickness 6.25 (5.62-6.87)μ; polar capsules 4.68(4.37-5.00) by 3.62 (3.12-3.75)μ. The iodophilic vacuole 1.90 (1.87-2.12)μ in diameter. 3, Henneguya weishanensis sp. nov.(Figs. 61-64). On the gills of Siniperca chu-atsi (Basil.). The fresh cysts are pad-like nodules in external view, measuring 3-4 millimeters in diameter, and surrounded by a thin layer of connective tissue. They con-tain four to nine small cysts which vary in size from 1.50-2.50 by 1.00-1.50millimeeters. The spores are fusiform shaped both in front and sutural views. Its anteriorendis somewhat pointed, while the posterior end prolongs smoothly into a bifurcatedtail. The sutural ridge is straight and distinct. The two pyriform polar capsules areequal in size and convergent. The intercapsular projection is indistinct. The sporoplasmcontains an iodophilic vacuole and two small nuclei. The capsulogenous nuclei are distinct.Dimensions of the fresh spores: length, including the tail 75.09 (62.50-87.00) μ,width 6.31 (6.25-6.87)μ, thickness 5.16 (5.00-5 .62)μ, length of tail 60. 10(47.50-73. 25)μ; polar capsules 4.53 (3.75-5.00) by 1.93 (1 .87-2.12)μ andiodophilic vacuole 1.20 (1. 00-1.50)μ.