An experiment of leaching of latosol developed from basalt with simulated acid rain was carried out.Results show 1) simulated acid rain caused a large amount of leaching loss of soil base ions, among which potassium was the easiest to get leached and calcium and magnesium were the highest in amount; the lower the pH values and the longer the duration of simulated acid rain, the higher the leaching amount of soil base ions; 2) after 5 days of leaching with simulated acid rain, the amount of soil exchangeable base ions decreased with the increase in leaching time; and the effect varied with pH of the simulated acid rain; 3) a short-time of leaching (≤5 d) increased contents of soil exchangeable Ca²⁺,K⁺,and the content of Mg²⁺ (when pH was ≤3.0) in the soil;however, a long-time of leaching (≥10 d) did reversely;and the content of soil exchangeable Na⁺ was always decreased no matter how long the leaching time was; and 4) leaching with simulated acid rain, triggered weathering of some soil minerals, thus releasing base ions, and turning some soil exchangeable ions into non-exchangeable ones as well.