Abstract: During large engineering project construction,the phenomenon which the low bid price often leads to high cost has its own inevitability. Chances to get contract affect the quoted price. Low price to sign contract promises that the project owner would gain excess profits. In construction this will leads owner and contractors to form an antagonized relationship at beginning, then come to term gradually, namely "antagonism to concession" relationship between owner and contractors. After contractors enter the building site, the owner whose losing risk coefficient turns to bigger tends to concession in order to ensure the project complete at the plan time. "Antagonism to concession" relationship between owner and contractors has a fluctuant balanced point, but at the process in which owner and contractors fight for profits, the resource was invisibly consumecL The article analyzed the phenomenon with mathematics model, and gave some suggestion which applied to management of large engineering project will avoid the phenomenon

Key words: low bid price, high cost, mechanism, chances to get contract, losing coefficient, fluctuant balanced point, "antago- nism to concession" relationship

摘要： 工程项目建设过程中，低标价中标而最终导致高造价的现象有其内在的必然性．中标机会大小影响报价变 动．低价中标预示业主取得了“超额利益”，导致建设期间业主与承包商存在利益上的先对抗、后妥协的“对抗—妥 协”关系．承包商进场后，业主风险损失系数大而趋向于“妥协”，以利项目按时完工．“对抗—妥协”关系存在动态平 衡点，但双方在争夺利益的过程中均付出了代价，资源被无形消耗．动态平衡点的计算也存在陷阱，用错也使造价 大幅提升．本文运用数学模型分析了其中的机理，并提出了防范和改变这种局面的建议，可应用于大型工程项目管 理．

关键词: 低标价, 高造价, 机理, 中标机会, 损失系数, 动态平衡点, “对抗一妥协”