Risk sharing，and benefit distribution are two important institutional arrangements of Member Heterogeneous farmers’ cooperatives，they determine the contract form and influence the stability of cooperatives. Taking three Chinese dairy farmers’ cooperatives as examples，this paper analyzes the logical relationships between，risk sharing，benefit distribution and cooperative stability. The study suggests that the cooperation stability between cooperative members and organizations has been influenced both by benefit distribution and risk sharing of cooperatives. If other conditions are under control and unchanged，the more risks cooperatives take，the stabler the cooperative relationships of cooperatives and members. If the surplus distribution mechanism between cooperatives and members is more distinct，the tendency degree for keeping a stable cooperation relationship of members and cooperatives will be relatively higher.