Compared with decentralized tendering procurement,concentrated one is more fair,efficient,strict and transparent so it has found wide use.In concentrated tendering procurement,the principal-agent relationship between tenders and bidders is the most important one.The tender need design incentive,restrictive and supervision mechanism respectively,of which incentive mechanism is precondition and basis,so it becomes the beginning of all.Compared with decentralized tendering procurement,the concentrated one can reduce the production cost and transaction one by enlarging the scale and reducing the times of attendance,so it is in-built incentive mechanism.