Abstract: In this paper three different karyotypes of wild rice species growing in China were examined, after the preparation of chromosome sample by wall degradation, hypotonic treatment and flame-drying method and stained with Giemsa, i.e., the karyotype of Oryza perennis: K(2n) = 24 =2Asm 20Bsm + 2tCsm; the karyotype of O. officinalis: K(2n) =24=4Am+18Bsm+2tCsm; the karyotype of O. meyeriana: K(2n)= 24= 6Am + 16Bsm + 2tCsm.