Comparative anatomical observation on stem and leaf of 40 common Labiatae species was performed by paraffin section technology.Typical anatomical characters of stem and leaf in dicotyledon were observed.(1)Stem were made of epidermis,cortex,and ascular cylinder.Developed collenchyma existed under the epidermis of the edge corner.Vascular tissues under the collenchyma were obviously more developed than other tissues.There were three types of stem cross section,three types of vascular bundle as well.(2)Leaves were comprised of epidermis,mesophyll and vein.As a bifacial leaf,palisade tissue and spongy tissue are apparently distinct.And the palisade tissue consists of 1-3 layer cells.Vein venter bulge was found in few species.In most of the species,main vein was more developed than lateral vein,and the others were nearly similar.There were three types of vascular bundle in vein,crescent,hemicycle and circular.The number of vascular bundle mostly was single or more in some cases.The mainly taper of epidermal hair was composed of 1-3 cells and few were rhabditiform.The results showed that,the anatomical characters of stem and leaf in Lamiaceae species is distinct whatever among the genus or species which was helpful for discussing the taxonomic position of species in Labiatae,as well as species identification.However,it can not be the determining character.