Abstract: Taking Pogostemon cablin leaves from six origins with identified chemotypes as test materials.A digital microscope system was used to observe and compare various microscopic characteristics of P.cablin leaves.Variance analysis,cluster analysis and principal component analysis were performed on microconstants,such as leaf vein islandsnumber,palisade ratio,stomatal index,non-glandular hair number,capitate trichomes number and peltate trichomes number using SPSS 21.0,MEGA 7 and SIMCA 14.1.This study could provide reference for the study of the relationship between the microscopic characteristics of P.cablin leaves and the chemotype classification and the quality evaluation of P.cablin.The results showed that the two chemotypes of P.cablin leaf were similar in epidermal cell shape,epidermal cell aspect ratio,stomata size and type.There were significant differences in leaf margin,leaf aspect ratio,the pattern of vertical wall,epidermal cell size,palisade ratio,leaf vein islands number,stomatal index,non-glandular hair number,capitate trichomes number and peltate trichomes number,which could be used as evaluation index for distinguishing different chemotypes of P.cablin.P.cablin from Sihui,Gaozhou,Leizhou and Yangchun city were classified as patchoulol-type,while those from Liantang and Longdong were classified as pogostone-type.