Purpose <p>Soil water storage is affected by forest type conversion through the changes in canopy structure and soil characteristics. Recently, large areas of natural broadleaf forests in China’s subtropical region have been converted into secondary forests and plantations. However, the impact of forest type conversion on soil water storage remains unclear.</p> Methods <p>Four forest types were selected, including natural forests, secondary forests, <i>Castanopsis carlesii</i> plantations <i>and Cunninghamia lanceolata</i> plantations. The temporal (rainy and dry seasons) and vertical (0–20&#xa0;cm and 20–40&#xa0;cm depths) variations in soil water storage were examined through one-year period monitoring.</p> Results <p>Soil water storage significantly increased by 5.4% after the conversion of natural forests to secondary forests, while there were no significant changes after conversion to <i>C. carlesii</i> plantations <i>and C. lanceolata</i> plantations. The differences in soil water storage after the conversion of natural forests to secondary forests mainly occurred within the 20–40&#xa0;cm soil layer. However, after the conversion of the natural forest to the other three forest types, the soil water storage did not change significantly in both rainy and dry seasons. Soil bulk density, soil pH, and rainfall were the dominant factors in regulating soil water storage.</p> Conclusion <p>Our study suggested that conversion of natural forests to secondary forests had more soil water storage than conversion to plantations, which highlighted the potential of secondary forests to contribute to improved soil water storage in subtropical forest ecosystems. These results will guide future strategies for enhancing soil water capacity, and provide support for sustainable management of forest resources.</p>