Changes in 7 water-soluble ions including SO₄^2-、NO₃^-、Cl^-、NO₂^-、 F^-、Br^-、PO₄^3- of rainwater were investigated in Camphor forest ecosystems in Changsha city, Hunan Province of China. Water samples were taken as rainfall above the forest canopy, throughfall, stemflow and surface runoff in the forests. The result showed that Br^- and PO₄^3- were not detected in all water samples. Both SO₄^2- and NO₃^- were the major inorganic anions in waters under Camphor forests, which accounted for 75.6-89.0% of the total anion contents in the forest ecosystems. The contents of anion decreased in an order: SO₄^2- > NO₃^- > Cl^- > F^- > NO₂^- in rainfall and stemflow; SO₄^2- > NO₃^- > Cl^- > NO₂^- > F^- in throughfall and NO₃^- > SO₄^2- > Cl^- > F^- > NO₂^- in surface runoff. The leaching coefficients were 3.8, 2.6, 4.2, 4.3 16.1; 7.5, 3.6, 4.3, 2.8 3.1; and 2.6, 4.7, 5.0, 3.0 3.6 for SO₄^2-, NO₃^-, Cl^-, F^-, NO₂^- in throughfall, stemflow and surface runoff, respectively. The pH value averaged 4.77 in rainwater and the ratio of SO₄^2-/NO₃^- was 1.1 in the study area, which indicated that the rainwater was a sulfuric-nitric mixed acid rain. A significant positive correlation was found between rainfall and throughfall for all anions, except for NO₂^-. The NO₃^- in rainfall was significantly and positively related to that in stemflow. There were a positive relationship of SO₄^2- and Cl^- between throughfall and stemflow and surface runoff. The pH was 5.62, 4.61 and 7.19 in throughfall, stemflow and surface rounff, respectively.Our results demonstrated that Camphor forest ecosystems had a relative high ability to purify acid rainfall through adsorbing, uptaking, leaching and neutralizing processes.