Abstract:Leaf anatomical structures of seven host plants of Ericerus pela (Chavannes) were observed under the microscope (NikonE800) with paraffin sectioning method, including leaf thickness, midrib, culticle, palisade tissue and spongy tissue, diameter of vascular bundle, ratio of palisade tissue to spongy tissue, and ratio of leaf thickness to midrib thickness. The results showed that there were significaut differences among genus and species of quantitative character and anatomical structures, which had taxonomic significance for classification of Ligustrum, Fraxinus and Chionanthus. Among seven host plants, the leaf surface of Fraxinus chinensis Roxb. and Ligustrum calleryanum Decne. had trichomes, while the others absent. Ligustrum lucidum Ait. had the maximum diameter of vascular bundle and the thickest of vein, spongy tissue and palisade tissue. Therefore, it may be important anatomical features of superior host plants of Ericerus pela that leaf surface is smooth with well-developed veins and thick lamina. Among host plants, well-developed main and lateral veins formed protrude on the abaxial surfaces and groove on the adaxial surfaces. However, a network of minor veins was present in the lamina of the leaf and these were too small to be visibly raised on either the lower or upper surfaces of leaf. So, it suggested that groove and protrude of veins provided key cues for settling sites selection of E. pela.