||Many software based on network analysis technique have been developed and proven effective in construction management especially scheduling of building projects. However, due to the complexity of building projects and the limitation of traditional software programming technique, these software are applicable only to a prepared network model of a project, and the data needed for establishing such model can not be extracted directly from the data existing already in CAD drawing generated at design phase. This paper presents an expert system ESSCAD developed for integrating construction scheduling with CAD drawing. The system, which was developed mainly with knowledge-based system programming technique and software integrating technique, can automatically interpret the CAD drawings of a building and extract data of its building components, breakdown the project into activities, determine the logic dependencies among activities, estimate the work quantities and durations of activities, finally generate a primary construction schedule for the project. As ESSCAD was integrated with a popular CAD drafting system, AutoCAD, and a popular scheduling software, Microsoft Project 4.0 for Windows, it retains the advanced functions of CAD drafting and network analysis. A sample application of ESSCAD to schedule a reinforced concrete frame structure building directly from its AutoCAD drawings is also presented.