Maize variety, Zhengdan 958 was used as experiment material, soils were treated with calcium carbonate (CaCO₃) at rates of 0, 0.3, 0.5 g per kg soil while soils treated with no plant were the non-rhizosphere soils, and then the effects of CaCO₃ and rhizosphere on phosphatase activity and the abundance of phosphate-solubilizing microorganisms (PSM) associated functional genes phoC and phoD in acidic red soil were studied. Results showed that CaCO₃ addition could effectively improve maize growth and promote the absorption of nitrogen, phosphorus, potassium and calcium in maize shoots. Soil acid phosphatase (ACP) activity was significantly higher than alkaline phosphatase (ALP) activity, indicating that the dominated effect of ACP in mineralizing organic P in acidic soils. The ACP, ALP activities and phoD gene copy number in rhizosphere soil were significantly higher than those of non-rhizosphere, while ALP activity and phoD gene copy number under Ca-0.5 treatment were significantly higher than those of CK, indicating that rhizosphere effect was stronger than CaCO₃ treatment. phoC gene copy number was significantly correlated with the contents of ammonium nitrogen and nitrate nitrogen, while both ALP activity and phoD gene copy number were significantly correlated with soil pH and the contents of ammonium nitrogen, nitrate nitrogen, available phosphorus and exchangeable calcium. It can be seen that both CaCO₃ and rhizosphere can affect the function and abundance of PSM in acid soil, but the rhizosphere effect is more obvious, which is closely related to the changes of soil physicochemical properties.