Three-year old Tilia amerensis Rupr. was taken as study subject in a pot experiment. Chlorophyll content, REC, peroxidase activity, SOD activity, and other indices of Tilia amerensis Rupr. leaves were assayed. The experimental results show that Pb contaminated and destroyed the chloroplast structure of Tilia amerensis Rupr. leaves and impeded the synthesis of chlorophyll in the leaves. When Pb concentration was 10 mg•kg-1–100 mg•kg-1, REC of the Tilia extract was roughly equal to that of the control group, and Tilia amerensis Rupr. leaves were contaminated by Pb to a small degree. When Pb concentration reached a higher level, REC increased rapidly and Tilia amerensis Rupr. leaves were contaminated substantially. Low Pb concentration may lower the POD activity of the leaves. However, when Pb concentration was high, the POD activity elevated and Tilia amerensis Rupr. could exhibit various reactions to instinctively defend itself. The SOD activity of the Pb-contaminated Tilia amerensis Rupr. was slightly higher than that of the control group, and the ROS content remained low. The SOD enzyme system was undamaged.