In order to explore new ways of improving the fertility of sand soil for planting tobacco in Nanxiong tobacco growing area,the change of physicochemical properties and related enzymes activity after mixed the sandy soil with different proportion of purple soil was studied by pot experiment.The results showed that when the sand soil was mixed with 10% to 50% purple soil,the sand content of the mixing soil gradually decreased to 11.57%,the silt content of the mixing soil gradually increased to 62.19%,the soil texture gradually changed from silt loamto loam,the pH values gradually became weak alkaline from slightly acidic,oxidoreductase enzyme activity was gradually increased,hydrolytic enzyme activity was gradually weakened,the contents of trace elements(except for molybdenum)were decreased,the amount of element content of exchangeable calcium and magnesium were 313% and 37.1% higher than CK1.When the sand soil was mixed with 30% purple soil,total K and slowly available K were 50% and 69.2% higher than CK1,but other nutrient contents decreased in varying degrees.The correlation analysis showed that soil enzyme activity was affected by the content of trace elements and the nutrient content.Catalase,polyphenol oxidase,acid phosphatase and neutral phosphatase significantly or extremely significantly correlated with pH,organic matter,total nitrogen,alkali hydrolyzable nitrogen,available phosphorus,total potassium and available potassium.The content of available copper,available zinc,available boron,exchangeable calcium and magnesium significantly or extremely significantly correlated with catalase,peroxidase,polyphenol oxidase and neutral phosphatase.It obtained by principal component analysis that the sand soil mixed with 10% purple soil had the highest comprehensive scores and had the best mixed effect.