Abstract: It is easier, for the high and middle administrations, to bring into full play the institutional advantage of mobilizing resources for major undertakings. To the grass-roots governance with decentralized tasks and mainly relying on localized management, whether and how can the institutional advantage be transformed into governance efficiency deserves a further study as in such a process there may come out a certain institutional distance, i.e. the gap of institutional effect produced by institutional texts through regulation, cognition and understanding under the centralized system. It mainly refers to the long-chain administrative level, and the cognitive attenuation of instructions from transmission to implementation. Recent years have witnessed local governments' having actively explored new models and paths of grassroots governance, thus gradually bringing forth a number of well-performed reform models, among which the most influential one is the whistle reform. In the reform, the new integration mechanism embodied in the same structure of government and society has obviously promoted the transformation of “system and efficiency” at the present stage. The isomorphism of government and society is a new integration mechanism oriented to solving problems, and it is the basic point to solve the problems of grass-roots governance. In order to reduce the institutional distance, the vertical and horizontal cooperation is realized through the isomorphism, and the target is more consistent. The government achieves the extension of the control tentacle through the isomorphism of the goal and business with the social subject. At the same time, the social subject in this mechanism bears remarkable vitality, which reversely stimulates the behavior of the superior governments in the grass-roots governance through the effective evaluation mechanism. Political and social isomorphism not only reflects the diversity of governance, but also avoids the fragmentation of governance. However, isomorphism also needs to be grasped, and importance should be attached to maintaining the cohesion and flexibility among the governments, society and residents.

Key words: institutional advantage, institutional distance, political and social isomorphism, governance efficiency, grassroots governance, whistle reform