In order to better understand the effects of electrodialysis and acid leaching treatments on the acidification process of purple soils, an acid purple soil with the pH value of 5.00 and a neutral purple soil with the pH value of 7.06 collected in Chongqing were treated by electrodialysis and acid leaching treatments for different days (1, 2, 5, 7 and 10 days, respectively). The variation of soil acidity and exchangeable base cations during these treatment processes were analyzed. The results showed that the pH values of both acid purple soil and neutral purple did not change significantly. This could be attributed to the high acid buffering capacity. The purple soils could not be acidified in a short-term acid rain leaching. Differently, after 10-day electrodialysis treatment, the pH values of acid purple soil and neutral purple soil decreased by 3.4 and 1.1, respectively. In the electrodialysis process, the soil exchangeable acidity increased significantly and the content of exchangeable base cations decreased greatly. It was indicated that electrodialysis could be used to rapidly acidify purple soil. The acidification degree of neutral purple soil after electrodialysis treatment was higher than that of acid purple soil. This was because the amount of negative surface charge of neutral purple soil was higher than that of acid purple soil, which caused that more acidic ions (H⁺ and Al³⁺) were adsorbed on the surface of neutral soil, correspondingly, resulting in the increased acidified degree of neutral purple soil. Therefore, compared to acid leaching treatment, electrodialysis treatment was a more effective way to acidify the purple soil in a short time. It also could help us to reveal the acidification mechanism of purple soil. After taking the feasibility of electrodialysis and acid leaching treatments into account, it was concluded that electrodialysis was an effective technique to study the acidification of purple soil.