The karyotypes of 8 populations of Coptis teeta,which distributed in different ecological areas (4 in east slope and the other 4 in west slope of Mt.Gaoligong),were studied using the methods of root tip squash and carbol fuchsin dyeing.The results show as follows:(1)In these populations,the chromosome numbers are same 2n=2x=18;(2)Except that the karyotype of one population in east slope belongs to 3A type,the karyotypes of rest 7 populations belong to 2A type;(3)Despite the fact that the karyotypical features appear to be similar for the populations in the same ecological area (i.e.east slope or west slope),large karyotypical differences exist among those populations in different ecological areas.First,the occurrence and numbers of acrocentric chromosomes (st chro.) and telocentric chromosomes (t chro.) are variable among the populations in the east and west slope.Second,the degrees of karyotype asymmetry of the populations in east slope are higher than those of the populations in west slope.