It is generally believed that rural economic development requires financial support. According to China's past experience, the rural formal financial system seemed firmly established, but its performance was not effective. Broadly speaking, the financial deposit from rural sectors flows into urban and non-agricultural sectors. More specifically, farmers have hard times obtaining loans and face high interest rates. To solve this problem, Chinese authorities have attempted to gradually develop an informal institution by means of micro-financial organizations and cooperatives to improve the supply of rural finance. This article adopts the institutional evolutionary experience of Puhan Community in Shanxi and explores the developmental logic of rural microfinance through some performance changes by institution constraints.