Abstract: The application of PPP in Haikou's sanitation service is a typical example in China. Based on the depth interview of the Haikou municipal government and the contractor in 2016, the paper concludes that the construction of the platform company, the reasonable investing proportion between public and private, the profitability ratio, the competition mechanism between companies, the transient policy for original staff and sanitation enterprises are key factors to success. The paper also holds the view that the way to solve the problem of the staff and the formation of detailed contract in financial, rights and performance assessment need to improve instantly.