Abstract: Based on screening germplasm resources of oolong tea plant with low pesticide residue content, the relationship between pesticide resistance and leaf morphology, anatomic characteristics of oolong tea plant resources was studied, and the resistance mechanism of tea plant to pesticide residue was probed into. The result showed that the pesticide resistance of tea plant resouces correlates with leaf tine, ratio of cutin layer/ palisade tissue, ratio of cutin layer/ spongy tissue, ratio of upper epidermis/ cutin layer. The tea plant resources with low pesticide residue content had the characteristics as follows: sharp leaf tine, low ratio of cutin layer to palisade tissue, low ratio of cutin layer to spongy tissue, high ratio of upper epidermis to cutin layer. The tea plant resouces with high pesticide residue content reversed. Key words: Tea plant; Pesticide residue; Resistance mechanism