Abstract: Cost control is an important part in project management and demonstrates management level and competitiveness of construction enterprises.After analyzing annual production，annual profit and annual profit margin of construction enterprises and the entire industry in the years from 1998 to 2008，the authors find out that profit margin of construction industry is much lower than national average.Therefore，the authors suggest that project control and management system be established and total cost management be implemented.Such efforts，together with effective utilization of design alteration and claim，will contribute to increase in profit margin of construction projects.

Key words: project cost, whole process, cost control, project management, construction cost, a market-oriented economy, enterprise management