【正文】 In order to improve economic benefits after winning the bid, many bidders often use unbalanced quotation. For example, they will reduce unit price of the project whose quantity will be reduced probably and increase unit price of the project whose quantity will be increased probably. Therefore, the bid evaluation experts should carefully judge whether every bid document exists obvious unbalanced quotation.The bid assessment experts should not only review the unit price carefully, but also pay close attention to the corresponding quantities. Especially, they should focus on the unit price of large quantities project and judge if the unit prices are in a reasonable interval range. In addition, the bid assessment experts should study the corresponding work content, construction plan, work requirements and field actual situation as well as the unit price.(3) Improve the preparation quality of Bill of Quantities. The accuracy of the quantity is the core of the project cost control and is also a key to limit unbalanced quotation. Therefore the experienced professional personnel should be arranged to be responsible for the job. The preparation of Bill of Quantities should strictly ply with Code of Valuation with Bill Quantity of Construction Works and should be prehensive and have the predictability. Meanwhile in order to make the bidders fully consider the expenses by pleting all list items and prevent future engineering cost increased, each list item must prehensively, accurately describe the characteristics and workcontents the bidders must finish. In view of the interface with cross engineering, the detailed bill of engineering quantities should be prepared to avoid interface work repeated or vacant [5, 6].（4）Further regulate the construction market. In order to promote the healthy development of construction industry and create a unified, open, petitive and orderly construction market environment, it is urgent for the government to take effective measures to rectify the state of chaos in the construction market. Firstly, the government must focus on renovating the prominent problems existing in the construction market. Secondly, the government should further perfect the construction market laws and regulations system. Last but not least, the government should improve the access and clearance system of construction market and strengthen the regulation of the market. Obviously, only the construction market is standardized further, it is easier for employer to control cost in the bidding stage [6, 8].（5）Vigorously cultivate and develop the intermediary service industry. It is necessary to establish the perfect intermediary service industry to greatly develop the construction industry. Although the intermediary service institutions are not the party to the contract between the employer and the contractor, they can provide all kinds of intellectual service for contracting parties. Therefore, in the implementation of the project they play an important role. And because the employer often don’t understand or isn’t familiar with the engineering construction business, they mainly provide the service for the employer at more time. For example, in the bidding stage, the intermediary service institutions such as the engineering cost consulting pany, bidding agency or project management panies may participate in the project. In their help, the contracting parties can be more fair, rational and effective to determine engineering price [6].ConclusionThe cost control in the bidding phrase is one of the most important links during the whole processes cost control. From what has been discussed above, it is drawn the conclusion that in order to better control the engineering cost in the bidding phase, the employer’s most important job is to prepare a highquality tender documents, as many important matters such as the bidding type, pricing pattern, contract type, construction drawings, contract terms, bill of quantities, evaluation criteria and method and so on are all parts of tender documents. In addition, the employer needs the highquality service from the intermediary service institutions such as the engineering cost consulting pany, bidding agency or project management panies and the standard construction market environment built by the government management departments and other market main bodies.References[1] F. Yang, Z. Shan, The initial search on the cost control in the bidding phase under the bill of quantities pricing mode, China Tendering, 9 (2007) 2528.[2] J. Guo, Y. Liu, Construction Estimating Management, Tsinghua University Press, Beijing Jiaotong University Press, (2008) 269270.[3] X. Zhang, The forming mechanism of the bidding price and the analysis on the bidding price, Science amp。 Technology Information, 6 (2009) 127.[4] X. Wang, J. Li, Engineering Bidding and Contract Management, China Machine Press, Beijing, (2009) 2931.[5] C. Zhang, The employer’s engineering cost management in the construction bidding stage, Airport Construction, 4 (2006) 4446.[6] Y. Ding, Some discussion on cost control during construction tendering and bidding period, Building Construction, Vol. 30 2 (2008) 148150.[7] X. Mao, The analysis on the cost control in the bidding stage, WestChina Exploration Engineering, Vol. 117 1 (2006) 294295.[8] Q. Gao, The deep analysis on the influence of the bidding to control and manage the engineering cost, Science amp。 Technology Economy Market, 9 (2007) 474820