[Obiective] Investigating the distribution of soil calcium on natural slope under the influences of integrated factors in order to better understand the structure and evolution of soil in karst area.[Methods] Typical karst peak-cluster in Yanbei Town, Yingde City, Northern Guangdong Province, was selected as the research area. The contents of total calcium, exchangeable calcium, water calcium and organic matter were measured, and correlation analysis were used.[Results] At the peak cluster, the average content of total calcium, exchangeable calcium and water soluble calcium was 4.172, 1.050 and 0.026 g/kg, respectively. Exchangeable calcium accounted for 22.29% of the total calcium, while water soluble calcium accounted for 0.56% of total calcium. The contents of total calcium, exchangeable calcium and organic matter reduced with the decrease of slope gradient. Contents of soil calcium in steep slope were obviously higher than that in the gentle one. The contents of water soluble calcium showed little changes with the slope variation. The correlation analysis showed that the total calcium and exchangeable calcium was positively related with altitude, slope and coverage of rock, while negatively related with soil thickness. There were no significant correlations between water soluble calcium and the topographical factors.[Conclusion] The topographical change and soil development influences the contents of total calcium and exchangeable calcium, while it has no significant influence on the contents of water soluble calcium. On the natural slope of karst peak-cluster, both total calcium and exchangeable calcium migrate with the slope descending, but the vertical migration is not obvious. The migration of water soluble calcium is not obvious, but it is sensitive to local hydrological conditions.