[Objective] The impacts of landscape patterns on the water conservation capacity of small watersheds in the southern Jiangxi Province were explored to provide a scientific basis for optimizing these patterns and thereby managing water resources. [Methods] The water conservation capacity of 1 030 small watersheds in the study area was calculated using the InVEST model. Fragstats 4.3 software was used to obtain landscape pattern indices， such as forest cover ratio （FCR）， number of patches （NP）， edge density （ED）， mean patch area （AREA_MN）， landscape cumulative index （LCI）， contagion index （CONTAG）， and Shannon diversity index （SHDI）. Pearson correlation coefficients and the response surface analysis method were adopted to analyze how the landscape indices of small watersheds influenced their water conservation capacity. [Results] ① Among the landscape pattern indices， FCR， AREA_MN， and CONTAG showed highly significant positive correlations with water conservation capacity （p<0.001）， whereas LCI， NP， ED， and SHDI showed highly significant negative correlations （p<0.001）. ② According to the response surface of water conservation capacity to FCR and LCI， when LCI<0.218 and FCR>80.65%， water conservation capacity increased slowly with increasing FCR and decreasing LCI； when LCI>0.272 and FCR<58.82%， water conservation capacity increased significantly with increasing FCR and decreasing LCI. ③ In small watersheds with low net precipitation input （463—607 mm） and high terrain index （19—24）， and in those with moderate net precipitation input （607—751 mm） and low terrain index （12—19）， water conservation capacity showed only weak response to FCR and LCI. [Conclusion] By adjusting forest cover ratio and landscape cumulative index， the water conservation capacity of small watersheds can be improved. However， the improvement range is closely related to the terrain and precipitation conditions of small watersheds.