As the increasing of project size and complexity of the project, quantitative management has been more widely used and promoted. Quantitative management allows businesses to be more active prediction, monitoring, control project of greater benefit. In this paper, with the quantitative management theory in CMMI4, based on the organizational-level process definition and according to metrics-driven decision making to determine which sub-project management process needs to be quantified. Through quantitative management of software projects intended to achieve the project expectations of quality and process performance objectives. Illustrates the practical significance of software project quantitative management for implemening information technology process management.