The development of Internet has changed the way of public political participation, and citizens’ participation in public policy through the Internet has become the trend of the new era. In the interaction between the government and the people, the people are consumers, they present their demands to the government, the government provides policies as products to the people to meet their needs. In the background of “supplyside” reform in China, as the public policy supplier, the government has the responsibility and obligation to improve public decisionmaking mechanism, so as to improve the quality of policies to meet the individual needs of the people. This paper has analyzed the opportunities and challenges that network development brings to the decisionmaking of the government. From many aspects, such as improving the government’s response mechanism; designing the longterm mechanism of network participation; establishing the consultation mechanism; establishing connection mechanism between the virtual world and the real world; establishing a mechanism of interest coordination and public opinion guidance, etc. This paper hopes these main five aspects may optimize the public decision supply mechanism in the new environment.