Abstract: The critical juncture theory is a new interpretation of historical institutionalism on how traditional institutions undergo sudden changes, proposing permissive and productive conditions for the formation of critical juncture, but without analyzing the stages of institutional change. The practice of managing the highly-priced betrothal gifts of the Yi Ethnic Group in Liangshan Sichuan provides us with a complete process of understanding institutional changes. In the stage of maintaining rural order, the absence of permissive and productive conditions leads to the continued historical inertia of path dependence on traditional order; in the stage of improving rural order, productive conditions arise in the countryside, but due to the lack of permissive conditions, traditional order has difficulty to undergo qualitative change; in the stage of mutating rural order, the requirements of external policies meet the permissive conditions of change, and the needs of endogenous forces meet the productive conditions of change. The combination of the two enables the effective implementation of the causal logic of critical juncture. It was found that in the process of mutation, party building guidance is a key factor, the awakening of the endogenous power of the masses is the fundamental motivation, and self-implementation is the guarantee for ensuring the change to continue.

Key words: critical junctures theory, conditions for institutional change, institutional change in the countryside, betrothal gifts, party building guidance