Abstract: The cytological characteristics of four populations of Allium wallichii in Liangwang Mountain area were comparatively studied. The results showed that population No.1 of A. wallichii was diploid, whose karyotype formula was 2n=2x=14=6m(2SAT)+8sm. Populations of No.2, No.3 and No.4 were all tetraploid populations, the karyotype formula of these three populations was the same as 2n=4x=28=8m(2SAT)+20sm. However, there were some differences in the ratio of the longest to the shortest chromosomes, in the morphology of the longest chromosome and in some other aspects among karyotypes of the three tetraploid populations. It was assumed based on the study results that the tetraploid A. wallichii was partially allotetraploid and it had experienced a long period of time in diploidization procedure.