Forest clear-cutting and subsequent habitat fragmentation cause catastrophic damage to plant and animal communities and the entire forest ecosystem. A number of studies have suggested that forest clear-cutting causes decreases in biomass and species richness in forests. However, the long-term influence of deforestation on local-scale diversity patterns is poorly understood. I investigated the land snail fauna in the soil of primary and secondary forests and compared the number of individuals and species richness of those forests. Two primary forests and two secondary forests in Kuromatsunai District (Hokkaido, Japan) were surveyed. As a result, a significantly larger number of individuals and significantly greater species richness were recorded in the primary forests than in the secondary forests. Specifically, the number of individuals of smaller species (less than 2.0 mm) was significantly decreased in the secondary forests, but that of larger species was not. I also estimated the age of the two secondary forests using an increment borer and found that both secondary forests were cleared approximately 100‒150 years ago. These results suggest that the past deforestation more than 100 years ago continues to impact the land snail fauna, thus affecting the soil fauna of the forest.