Abstract: The paper aims to find the suitable intermediate hosts of breeding Trichogramma japonicum (Ashmead), the authors draw up the life table of T. japonicum, compared and analyzed it’s reproductive parameters, and evaluated the suitability of T. japonicum to the two intermediate hosts which were eggs of the Plutela xylostella (L.) and Spodoptera exigua (Hǜbner). The results showed that: the reproductive parameters such as net reproductive rate (R0), intrinsic increase rate (rm), finite increase rate (λ) and mean generation time (T) of T. japonicum on the eggs of P. xylostella were 6.12, 0.1996, 1.2210 and 9.0728，respectively. Whereas those parameters on the egg of S. exigua were 10.58, 0.2573, 1.2934 and 9.1678. The reproductive parameters on the egg of S. exigua were better than that on the egg of P. xylostella. Thus, the eggs of S. exigua is more suitable host for that of T. japonicum.