Abstract: The four principles for benefit allocation among cooperative partners in a supply chain were proposed,i. e.more pay for more work, venture compensation, effectiveness maximization and comprehensive optimum. Three models of benefit allocationwere set up respectively based on the first three principles, and three schemes of benefit allocation were designed for different resources input, possible venture and effectiveness product. To take the importance of the three principles under the different conditions in benefit allocation into account, an improved colony barycenter model was adopted, and the concept of essentiality modulus was introduced. At last, a calculation example was given to explain the application of the improved colony barycenter model in benefit allocation among cooperative partners in a supply chain.