The chromosome numbers and karyotypes of the freshwater planarians,Dugesia japonica,from Xiahushan and Panguxi in Tongbai County,Henan Province were studied by air-drying method. The results showed that D. japonica collected from Xiahushan had a diploid number of 16 with a chromosome formula of 2n = 2x = 16m. D. japonica collected from Panguxi had a triploidy number of 24 with a chromosome formula of 2n = 3x = 24m.