【Objective】The aim of the present research work was to study the effects of interplanting banana and pueraria with young rubber on the soil fertility and enzyme activity.【Method】Banana and pueraria were planted between two rows of rubber trees (planted during July-August 2006) in April 2008. The samples from rubber plantation soils were collected 7 times from July 2008 to January 2010 in order to analyze the nutrient contents and enzyme activity of soils. The soils， which have not been interplanted， were taken as the control.【Result】The organic matter content， total nitrogen， available phosphorus and potassium content in young rubber plantation soils increased after intercropping， especially with banana. Interplanting both the banana and pueraria with young rubber were found to raise soil urease and phosphatase activities. The highest urease and phosphatase activities were observed in soils after interplanting with banana， followed by the pueraria and control. Interplanting pueraria in young rubber plantation enhanced soil catalase and polyphenol oxidase activities. However， activities of these two enzymes decreased after interplanting with banana.【Conclusion】Intercropping young rubber with banana and pueraria improved the soil fertility and microenvironment. Practicing of interplanting rubber with other crops may be recommended not only to improve the soil nutrient status but also to enhance the economic benefits to the farmers.