Abstract: The experiment was initially analysing differences in chromosomal karyotype of 15 populations in Houuuynia cordate Thunb. with the method of essential balm.The results showed that the chromosome numbers and the karyotype formulae were as follows: hefei：2n =20=14m+6sm；chaohu :2n =24=16m+8sm；wuhu：2n=20= 14m+6sm；guangde：2n=26=16m+10sm；tongling：2n=24= 18m+6sm；chuzhou：2n=22= 14m+8sm；huangshan： 2n =22= 18m+4sm；jixi：2n=24=14m+10sm；shitai： 2n =30=20m+10sm；huoshan：2n=22=14m+8sm；anqing： 2n =20=10m+10sm；dujiangyan：2n =32=26m+6sm；luzhou：2n =32= 22m+10sm；zigong;2n =32=18m+12sm+2t；neijiang：2n =30= 20m+10sm；the chromosome mumbers were 20、22、24、26、30、32, of which the number of 20,26,30 and 32 were found for the first time .So, the chromosome mumber and karyotypic were different among diffrent populations.

Key words: Houuuynia cordate Thunb., populations, karyotype