Two new species of myxosporeans (Myxosporea: Bivalvulida), Mitrapora yiduensis sp. nov. and Myxobolus tuenfengensis sp. nov.,parasitic in freshwater fishes collected from the Yangtze River of China are described in this paper. All body organs of the host fishes, Siniperca chuatsi Basilewsky and Saurogobio dabrui Bleeker were examined and twenty spores of each myxosporean were measured with an eyepiece micrometer. All the measurement are in micrometers (mum) and the type specimens were deposited to Department of Fish Disease,the Institute of Hydrobiology, Chinese Academy of sciences, Wuhan, China. 1. Mitrapora yiduensis sp. nov. (Fig. 1) Host: Sinperca chuatsi (Basilewsky) Location : Kidney Locality:Town of Yidu, Hubei province. (30degree31'N, 111degreeE) Date : May 1982. Vegetative forth: Trophozites are amoeba-shaped about 20.6(18.5-23.2)1)by 18.4(16.5-20.6)in size. Spore: Bell-shaped in both thecal and sutural view. Blunt circular at anterior end and a truncate posterior end. Sutural ridge is straight. There are six lines on surface extending from the anterior end to the posterior end of the spore. Two pyriform polar capsules are equal in size and sporoplasm have an indinopilous vacuole and two round germinal nuclei. Dimension of spores preserved in 4% Formalin: Length 8.1 (7.2-8.4), width 5.2 (4.8-5.5), thickness 5.9 (5.8-6.2);length of the polar capsules 3.0 (2.8-3.2), width 2.1 (2.0-2.2). This species is similar to Mitraspora coreosiniperca Xiao at feng, 1997, but the latter have a larger spore than the former and the former is blunt at anterior end of the spore, while the latter is slightly sharp at anterior end. 2. Myxobolus tuenfengensis sp. nov. (Fig. 2) Host: Saurogobio dabryi Bleeker Location : Gill Locality: Tuanfeng Town, Hubei province (30degree20' N,111degree5'E) Date: June 1984. Cyst: Round or elliptical shaped with 0.3-0.5mm in size. Spore:Ovoid or nearly ellipsoid in thecal view and spindle in sutural view. The anterior end is truncate and the posterior end is blunt. The sutural ridge is rough and straight with distinct intercapsular appendix. Two pyriform polar capsules are equal in size. Sporoplasm is even, with an iodinophililous vacuole and two round germinal nuclei. Dimensions of preserved (in 4% Formalin) spores: Length 12.8 (12-13.6), width 9.4 (8.4-10), thickness 6.6 (6.0-7.0); length of the polar capsules 4.5 (4.0-5.0), width 3.0 (2.9-3.2). This species is similar to Myxobolus mesentricus Kudo,1919 and Myxobolus haichengensis Chen, 1998. But the spore of our new species is larger than the other two species and they also differ in the size and form of polar capsules.