The problems like exceeding estimated cost, late due-date, expensive maintenance, insuffiency of experts and low productivity are becoming emphasized related with the software development. In order to overcome these problems and to develop the highly qualified software within the limited resources, a project management tool is used. The purpose of this study is to develop a conceptual model of the project management system which can plan, analyze and control the software development projects effectively. The model is constructed with plan and track management system, cost management system and operation management system for the efficient project management. It is named by LSD-PMS : Large-scale Software Development Project Management System. We reviewed 5 cases of project management. LSD-PMS is evaluated and reviewed by the project managers in the field. It is proved that LSD-PMS is a tool which can help project managers develop software successfully given budget and time schedule. In the future, this system should be further developed as an integrated model with system implementation tools such as CASE products.