Abstract: The barks of seven host tree species of Kerria lacca were observed. The results were as follows: All host tree species consist of periderm, cortex and secondary phloem, but in different layer, the structure of different host tree species had difference. The periderm of Flemingis macrophylla was the thinnest among seven host tree species, and the cortex of Albizia lucidior was the thinnest. In periderm of Koelreuteria paniculata and Acacia montana, the phellem was remarkably thick in certain places, and phellem of Zizyphus mauritiana had keratinaziation distributing as dots. The layer of sclereids and fibres of Zizyphus mauritiana was the thickest with four layers, but there were not continuous layers of sclereids and fibres in Ficus racemosa and Acacia montana. Acacia montana had the thinnest phloem, Ficus racemosa had the thickest phloem. Koelreuteria paniculata had the shortest min distance between periderm and phloem, and Acacia montana had the shortest max distance between periderm and phloem. Acacia montana had the smallest sieve tube density. In the area of sieve tubes with function, Flemingis macrophylla, Koelreuteria paniculata, Zizyphus mauritiana had simple column ray, seldom had several column of rays, Schleichera oleosa, Ficus racemosa, Albizia lucidior each had simple column ray, double column rays and several column of rays, Albizia lucidior. only had several column of rays.By analyzing the anatomic characteristics of phloem thickness,sieve density of host tree,the effects of different host tree species on the adhesion density and mortality of K.lacca were studied.