Chromosome number and polyploidy level identification were made on 50 accessions of wild Setaria species including S.viridis,S.faberii,S.verticillata,S.verticilliformis,S.glauca,S.parviflora,S.pumila,S.grisebachii,S.leucopila,S.queenslandica.All the S.viridis samples were found to be diploid,S.glauca samples had tetraploid and octoploid types,S.verticillata samples had diploid and tetraploid and all samples of S.faberii were tetraploid.One S.pumila sample was found to be diploid and other samples of the same species were tetraploid,and the diploid S.pumila would be important for genome composition study because it was the first diploid sample found in glauca group of Setaria genus.Among the three species,which were the first time ploidy level identification reported,S.grisebachii and S.grisebachii were diploid and S.queenslandica was a tetraploid species.