Abstract: Bidding is a battle of wits. If a bid is too high, the contract cannot be got, what’s more, the time, manpower andmoneythathave been spentforbidding arewasted. In contrast, ifone bidsmuch lower than his rivals, he obtains the contrast, but he“leavesmoneyon the contrasttable”. Therefore, a good bid must be calculated quantitatively with several different methods, and be selected through comparing the results given by these methods. In this paper a mathematical model based on fuzzy similar-priority comparison is established. It is used to forecast the price of bidding for engineering projects, and its effectiveness is shown by a practical example.