Abstract: The interaction effects between characteristic biochemical components of tea plant and Apolygus lucorum(Meyer-Dür) was explored, HPLC and UV-Vis were useded to analysis tea biochemical substances in healthy tea leaves and A. lucorum damaged tea leaves. The correlation coefficient between A. lucorum damages index and tea biochemical substances were analysised, the change of tea biochemical components after feeded by A. lucorum were also analysized. The results indicate that the content of caffeine and gallic acid were significantly positively correlated with the tea tree resistant to A. lucorum, while the free amino acids and EGC played the opposite role. Caffeine increased remarkably after damaged by A. lucorum. However, gallic acid dropped off remarkably. Caffeine is the key biochemical component of tea plant to resistance A. lucorum. The lightest damaged tea cultivars TX0310 contains the richest caffeine, and also gained the most after damaged by A. lucorum.