Citizen participation is one of the essential issues for democracy. The value of democracy cannot be realized without citizen participation. Taking citizen participation as citizen power, this book studied on 6 cases which represented different levels of citizen power. The six cases included: participatory budgeting by Township Chinese People'' s Congress, public policy advocacy, NGOs participation in government procurement, participatory governance in urban communities, participation governance by farms'' organization in rural area, and participatory governance among the migrant workers. The book studied the essential mechanism, principles, problem, results, and preconditions of the cases.