In this paper, how to effectively control building cost under the current situation is discussed, due to that the engineers take part into project management only in the stage of construction. It points out that the engineers should notice the following issues when applying cost control: they should be experienced with necessary knowledge on building cost and contracts control, analyze each cost in bills of project volume carefully, sign a set of reasonable contracts, pay attention to the site sign, understand their skills of claim for compensation and pay much attention to cost control during settlement stage.