Abstract: 5-6th instar mealworm (Tenebrio molitor) larvae and a singlefactor randomized design were used to study the effects of alfalfa (Medicago sativa) and white clover (Trifolium repens) diet on growth performance and body compositions of Tenebrio molitor with two treatment groups (clover group fed with white clover hay and alfalfa group fed with alfalfa hay) and one control group (wheat bran group fed with wheat bran). The results showed that the dry matter intake of clover group was at the normal level, but that of alfalfa group was far lower than that of control group (about 1/4 of the control). The weight gains, nitrogen depositions, ether extract depositions of mealworm larvae among three groups were significantly different (P0.01) and the order was alfalfa group clover group control group. At the end of experiment, the differences of crude protein contents and ether extract contents of mealworm among three groups were significant (P0.01); the orders were alfalfa group clover group control group, alfalfa group clover group control group respectively; the energy value of mealworm among three groups were similar. As for mortalities and pupation rates, there was no significant difference between two treatment groups, but significantly lower (P0.01) than control group.