To determine the roles of ectomycorrhizal fungi (EMF) in plant growth at different successional stages, we investigated the growth and ectomycorrhization of Pinus thunbergii and Lithocarpas edulis seedlings, grown on four types of soil : P. thunbergii forest soil (P-Soil), sterilized P-Soil (SP-Soil), L. edulis forest soil (L-Soil), and sterilized L-Soil (SL-Soil) from Sakurajima, where volcanic eruptions have formed various stages of succession. No mycorrhiza formed for either species on sterilized soil. The mycorrhization rate of P. thunbergii seedlings was significantly higher on P-Soil than L-Soil, while the rate of L. edulis seedlings did not differ significantly between these soil types. The growth of mycorrhizal P. thunbergii seedlings was significantly greater than that of non-mycorrhizal seedlings on both forest soils, indicating the importance of EMF in the growth of P. thunbergii seedlings. Conversely, the growth of mycorrhizal L. edulis seedlings was similar to that of non-mycorrhizal seedlings on both forest soils, suggesting that the initial growth of L. edulis seedlings was mainly influenced by nutrients from acorns.