Based on the analysis and study of the controllable factors of project investment and their influence degree in various construction stages of project,as well as the practice of investment control in the engineering construction of Kungang Dahongshan iron mine,this paper presents the emphasis to control investment in various construction stages of project.By adopting a series of active and effective control measures,such as the comparison and demonstration of many schemes,the optimization of construction drawing,rationalization proposals,the optimization and adjustment of major special measures,the controlling and management of construction process,as well as the examination of engineering settlement,etc.,the investment,construction time and quality of Kungang Dahongshan iron mine project all were controlled within the range of scheduled target,the completion and entering into production of Dahongshan project with 4 millions ton of ore each year a year has been realized with characteristics of speediness,high quality and low investment.