The negotiations before the final bidding mainly carry out two aspects of the negotiations: technical negotiations (also called technical defense) and economic negotiations (mainly price issues). In the international bidding activities, sometimes in the negotiations before the final bid allows the bidder to put forward the requirements of the price; in the use of the world bank loan project and our domestic project bidding activities, after the opening of the bidding is not allowed to lower the bid, but in the terms of payment, the payment period, loans and interest rates, as well as the rate of foreign exchange can be negotiated. Negotiation before the final bidding on the side of the bidder is through the bid evaluation committee to complete. This stage of negotiation to achieve the purpose, in the bidder, one is to further understand and review the candidate unit of technical programs and measures are reasonable, advanced, reliable, and ready to invest in the force is strong enough to ensure the quality and progress; two is to further review the offer, and in the payment terms, payment term and other preferential terms and conditions, such as obtaining the commitment of the candidate unit of the winning bid. In terms of the candidate winning unit, is to strive to make themselves the winning bidder, and to sign the contract on the most favorable terms possible. At the same time, the candidate winning unit can also inquire about the intentions of the bidder, to throw his favor, in order to promise preferential terms that do not involve changes in the substantive content of the bidding documents, to enhance their own competitiveness, and strive to win the final bid. The purpose of negotiation after the final bidding is to materialize and organize the agreement reached by the two parties before, and to legally certify all the terms of the contract to complete the final preparatory work for signing the contract agreement. Generally speaking, the post-bidding negotiation will involve all the commercial and technical terms of the contract, and the following are the main contents that may be involved: (l) confirmation of the content and scope of the contract; (2) technical requirements, technical specifications and technical programs; (3) price adjustment terms; (4) payment of contractual sums; (5) duration of the construction period and the maintenance period; (6) settlement of disputes; and (7) other issues relating to the improvement of the contractual terms. Of course, in the process of contract performance, the emergence of differences or disputes may also form the two sides of the negotiation situation, but in general, this time the contract has been formed to solve the problem is often local or non-fundamental, can be resolved through the interpretation of the contract or with the help of third-party forces to solve.