The pH value, electric conductivity of soil acidity and alkalinity, and neutralization capacity of acid were analyzed comprehensively for 9 kinds of soil. The results showed as following: That black soil and meadow soil were the best for seedling nursery of rice, the optimal range of pH values was 3.90-4.24, and at the same times, the calculation method(${\rm{\hat y}}$=0.036 7+0.038 8x)of the appropriate acid was cleared when the acidity of the nursery soil was regulated for the neutral soil and weak acid soil of weaker buffer properties. The objective of the experiment was to provide theoretical basis for the regulation of acidity of the dry seedling nursery soil of rice.