Soil acidification is a main form of soil degradation and also a main factor limiting sustainable development of agriculture therein. In recent years, due to aggravating acid deposition and frequent agricultural practices, including increasing fertilization rate, harvesting crops with nutrients removed, etc., soil acidification of the farmlands is speeding up. Therefore how to ameliorate or remedy acidified soils and its mechanism have become subjects of some important theoretical and practical significance to rebuilding healthy soil and guaranteeing national food security. Based on a 34-year long stationary fertilization experiment, effects of no fertilization (CK), application of NPK fertilizer (NPK) and application of NPK fertilizer plus lime (NPK CaO) on soil pH, exchangeable acidity, hydrolytic acidity, soil cation exchange capacity, base-exchangeable ions, rice yield and plant cation absorption, and further on proportion of exchangeable H⁺, Al³⁺ to exchangeable acidity, soil base-exchangeable ions, base-exchangeable ions removal by plant with harvest and their relationships with soil acidity. Results show that long-term application of chemical fertilizers (NPK) leads to soil acidification, and mitigates the effect when lime is amended (NPK CaO). After 34 years of rice cultivation of double cropping system, Treatment NPK was 0.2 and 0.3 lower in soil pH, 2.3 and 4.2 times higher in exchangeable acidity, and 35.4% and 40.0% higher in hydrolytic acidity than CK (p＜0.05) in the soil under early rice and under late rice, respectively, while Treatment NPK CaO was 0.5 and 0.7 higher than NPK, and 0.3 and 0.4 higher than with CK in soil pH in the early and late rice seasons, respectively, and much lower than Treatment NPK and CK in exchangeable acidity and hydrolytic acidity in both rice seasons (p＜0.05). In terms of exchangeable H⁺ and exchangeable Al³⁺, the three treatments in the experiment followed an order of NPK CaO ＞ CK ＞ NPK. Exchangeable Al³⁺ was dominant to exchangeable acidity in acidic soil, and the ratio of exchangeable Al³⁺ to exchangeable acidity increased with increasing soil acidification. The effects of fertilization, regardless of fertilization mode, on soil CEC, exchangeable Ca²⁺, Mg²⁺, exchangeable base ions and base saturation were all very significant. Soil exchangeable base ions were dominated with exchangeable Ca²⁺, accounting for 81.8%-89.3%. Long-term liming significantly increased the content of soil exchangeable Ca²⁺ . Treatment NPK CaO was 40.1% and 62.9% higher in soil exchangeableCa²⁺ than Treatments CK and NPK, respectively. Exchangeable Ca²⁺, exchangeable base ions and base saturation were positively related to soil pH, but negatively to exchangeable acidity and hydrolytic acid, and exchangeable Mg²⁺ was negatively to exchangeable acidity and hydrolytic acid, while exchangeable Na⁺ was negatively to hydrolytic acidity only. Treatments NPK CaO and NPK did not vary much, but were both significantly higher than CK (p＜0.05) in yield of early and late rice. In terms of calcium uptake by rice, the treatments followed an order of NPK CaO ＞ NPK ＞ CK, in terms of potassium and magnesium uptake and total cation uptake by the crop, the followed an order of NPK ＞ NPK CaO ＞ CK, and in terms of sodium uptake they followed an order of CK ＞ NPK ＞ NPK CaO. The removal of Ca, Mg, K and Na and the cations in total with the crops harvested did affect soil pH, exchangeable acidity and hydrolytic acid to a varying extent, but no apparent relationships between them were observed. The findings in this experiment indicate that long-term fertilization plus liming significantly raises soil exchangeable Ca²⁺, exchangeable base cation and base saturation. From the angle of amelioration of acidified soils, long-term liming in addition of fertilization may alleviate the pressure of soil acidification of paddy fields to a certain extent and hence promote ecological remediation and ameriolation of acidic paddy soils.