The soil incubation test was carried out to study the nutrient supply and acidity regulation ability of silicon-calcium-potassium-magnesium(SCPM)fertilizer and citric acid compound silicon-calcium-potossium-magnesium(CA-SCPM)fertilizer on the acid red soil and calcareous fluvo-aquic soil.The addition amount of SCPM fertilizer was 6 g/kg and the ratio of SCPM fertilizer and citric acid(CA)was 88%∶12%.Compared with control treatment，the pH value of red soil was increased by 1.16 units and the pH value of fluvo-aquic soil was increased by 0.19 units with the treatment of SCPM fertilizer and CA-SCPM fertilizer after 150 days of culture.For the red soil，SCPM and CA-SCPM treatments significantly increased the contents of available potassium，exchangeable calcium，exchangeable magnesium，soluble calcium，soluble magnesium，soluble silicon and available silicon.For the fluvo-aquic soil，SCPM and CA-SCPM treatments improved the contents of available potassium，available silicon and water-soluble silicon，but reduced the contents of exchangeable calcium，exchangeable magnesium，soluble calcium and soluble magnesium.CA had no significantly influence on the nutrient availability of two soils.The improvement effect of SCPM fertilizer on the red soil lies in an increase of soil pH，base cation content and available silicon content；while the positive effect on the fluvo-aquic soil mainly results from raised available potassium and silicon content，and the comprehensive effect is better when CA is introduced into SCPM fertilizer.