The chromosome number and karyotype of Pseudogyrinocheilus prochilus were analyzed using a routine method including intraperitoneal injection of PHA（phyohemagglutinin）and colchicine，cultivation in vivo，and slides preparation with air—drying．While erythrocyte nuclear DNA content of P. prochilus was determined by using a flow cytometer (Beckman Coulter Inc.,USA) with serving the chicken（Gallus gallus） erythrocytes (their DNA content is 2.50 pg/2c) as reference cells. The results showed that the diploid chromosome number of P. prochilus was 2n = 50, and the karyotype of this species was 2n = 12m + 14sm + 14st + 10t，NF = 76（Fig.1 and Tab.1）. The heterosomes were not observed. The diploid cellular DNA contents of P. prochilus was 2.62± 0.10 pg/2c（n=20），which was 1.05± 0.04 times to the chicken erythrocytes (Fig.2). The result of karyotype and DNA contents of P. prochilus showed that P. prochilus was diploid.