In contemporary European policy discussion, “innovation“ is a term popularly used for finding responses to the pressure of global competition. In various forms of innovation, the accent is mainly given to technical and business innovation but less to social innovation. This article studies the issue of social innovation with reference to the local practice in Hangzhou city, which aims to strengthen the life quality of citizens in this city. These practices develop various forms of inter-sectoral collaboration, resulting in numerous "common denominator subject" (CDS) groups that are promoted by the local government. These practices follow the principles of cooperation and partnership, and thus develop a corporatist mechanism for urban development. Through discussion of these practices this article explores the nature and the features of these CDS groups, and evaluates its meaning for social innovation, local administration, life quality and social quality.