Abstract: The present paper recorded the karyotypes of bone marrow cells of three species of the squirrels collected from southern China.Among them,the karyotypes of two geographical subspecies of Red-abdomen Squirrel (Callosciurus erythraeus castanecventris and C.e.michianus) were much alike.They were found to possess the diploid chromosome number of 40 (I.e.2n=40),FN=72,including 7 pairs of metacentric chromosomes,8 pairs of submetacentric ones,2 pairs of subtelocentric ones and 2 pairs of telocentric ones.No.18 was a pair of subteloentric chromosomes with satellites on the short arms.X-chromosome was a larger metacentric chromosome,Y-chromosome was a smallest subtelocentric one.The differences of the two karyotypes were just the variation of the arm ratio and of the relative lengths of some chromosomes (No.3.4.5.10.11.X and Y).In pernys Long-nosed Squirrel (Dremomys pernyi flavior),2n=40,FN=70.The 19 pairs of autosomes consisted of 8 pairs of metacentric chromosomes,8 pairs of submetacentric ones and 3 pairs of telocentric ones.No.18 was a pair of telocentric chromosomes absent from satellites,though a little below the centric there was a characteristiric ones;Y-chromosome was a medium submetacentric one.In Forrests Rock Squirrel (Sciurotamias forresti),2n=38,FN=72.The 18 pairs of autosomes consisted of 8 pairs of metacentric chromosomes,9 pairs of submetacentric ones and a pair of subtelocentric one,which (I.e.No.18) satellites on the short arms as Calllosciurus erythraeus.Sex chromosomes of both sexes were metacentric chromosomes,among them,X-chromosomes were larger,but Y-chromosome was the smallest.In the last part of this paper,we compared and analyzed the karyotypes of four genera of squirrels in Callosciurini tribe (Sciuridae,Rodentia) and discussed evolution of their karyotypes.