Abstract: In recent years, the spread and explosion of Merremia boisiana in Hainan has significantly threatened biodiversity and ecosystem functioning in the locality. The purpose of the study was to understand the impacts of the invasion of M. bosiana on the soil ecosystem properties. Through the analysis of sampling, we compared the changing patterns of soil physical and chemical properties and soil enzyme activities with the change in the level of invasion by the native harmful plant M. boisiana. The results showed that with the increase of the coverage, M. boisiana increased the soil organic matter, total nitrogen, ammonium nitrogen, nitrate nitrogen, available phosphorus, available potassium content,reduced the soil total phosphorus content, did not affect total potassium content, and also increased the activities of sucrase,urease and phosphatase. Organic matter, total nitrogen, ammonium nitrogen, nitrate nitrogen, available phosphorus and available potassium content in the heavily-covered soil was 44.96, 2.57 g/kg, 8.96, 17.42, 1.37, 12.67 mg/kg, which was 4.40, 10.28, 2.30, 1.57, 1.83 and 1.90 times as that in the non -covered soil. The activities of sucrase, urease and phosphatase in the heavily-covered soil was 3.39, 0.52, 7.70 mg/g, which was 2.92, 2.26, 1.39 times as that in the noncovered soil. The results indicated that M. Boisiana changed the soil physical and chemical properties and enzyme activities, probably creating a favorable soil environment for itself. This may be one of the ecological mechanisms underlying its invasion success and rapid expansion。