Standard plant root tip cytology research methods were used to study the chromosome number and karyotype of 5 populations of 3 Elsholtzia species. The result showed that:（1）the chromosome number of E. densa was 2n=16, and the chromosome number of E. flava was 2n=20, which were consistent with previous reports. Chromosome number of E. eriostachya was 2n=10, which is first reported here.（2） Cluster analysis results showed that E. flava has close relationship with E. densa. Only diploid and tetraploid were found in this genus and dominated by diploid.（3）Three conclusions were drawn by analysis of karyotype parameters: the karytypic formulae of E. densa Daocheng Wumingshan population 1 was 2n=2x=16=14m+2sm, and population 2 was 2n=2x=16=16m. CI of population 1 and population 2 were 39.57 and 42.32, AI were 2.75 and 2.87, respectively. The two populations have the same type of karyotype: 1A. The karytypic formulae of E. eriostachya was 2n=2x=10=10m, CI was 41.76, AI was 5.25 and the type of karyotype was 1B. The karytypic formulae of E. flava was 2n=2x=20=14m+6sm (Kunming population) or 2n=2x=20=16m+4sm (Nielamu population). CI of Kunming population and Nielamu population were 38.49 and 40.97, AI were 4.20 and 4.30, respectively. The karyotype types of Kunming population and Nielamu population were 1B and 2B.