The susceptibility of eight tomato cultivars to infestation with tomato leafminer in relation to leaves chemical composition was studied during the years 2018-2019 under Egyptian field condition. Four tomato cultivars; 714, 53, Alissia and G.S.12 were planted in early-summer plantation, while the four cultivars namely 86, 036, Fayrouz and Omnia were planted in nili plantation. Survey of eggs, larvae, mines and % of infested leaflets were estimated for all mentioned cultivars, whereas, the quantitative variations of the metabolites components applied for healthy and infested plants. Results indicated that, seasonal abundance of this pest was higher in early summer plantation than nili one. Moreover, the pest population decreased in 2019 than that recorded in year 2018 in both plantations. The most susceptible cultivars to the infestation were G. S. 12 and Omnia in early summer and nili plantations, respectively. On contrary, 714 and 86 cultivars appeared to be more resistant ones in both selected plantations. There were significant differences between tested compounds in all cultivars in healthy and infested plants and remarkable decrease of these compounds in infested plants, except for -esterase. Knowledge of the extent of durability of cultivars to a pest on a crop is one of the fundamental components of integrated pest management (IPM) programs for any crop.