Soil mesofauna can be used as an indicator of soil fertility on post-tin mining reclamation land. The diversity of soil mesofauna depends on climatic conditions and soil characteristics at its habitat. The purpose of this study were to determine the diversity of soil mesofauna at various ages of post-tin mining reclamation on Bangka Island and to determine the relationship of soil mesofauna diversity at various ages of post-tin mining reclamation land on Bangka Island with the soil characteristics. This research was carried out in January-March 2021 in reclamation land with different ages (2 years, 4 years, 6 years and 26 years) and forest site as control (comparison data). The method used is a survey method and sampling with a stratified random sampling method using pifall trap. The results showed that the diversity of soil mesofauna in reclamation aged 2 years, 4 years and 6 years, and control forest was in the medium category while the 26 years old reclamation land indicated as low diversity. The age of reclamation affects the soil mesofauna’s diversity index, the higher the age of reclamation land have higher diversity index, except for the 26 years old reclamation. The soil mesofauna diversity index has a very high correlation with soil and air moisture, a very low correlation with air temperature, a moderate correlation between air temperature and soil pH, while the C-organic content is opposite or negatively correlated with the diversity index and evenness index of the soil mesofauna.