Abstract:The chromosomes number and karyotype of 3 genera 4 species of Liliaceae in Ziwu mountain of Gansu province were reported in this paper.Those are as follows: P.megaphyllum 2n(2x)=22=4m+12sm+12st+6st,karyotype is 3B; P.odoratum 2n(2x)=20=12m(2SAT)+8sm