Information processing is critical to the successful development and execution of a construction project plan. Currently, Building Information Modeling (BIM) has been widely used in representing the physical and functional characteristics of design and construction. However, in order to use BIM effectively in construction project planning, more construction knowledge should be transformed and integrated. This paper proposes an activity-based modeling approach to process project information in an organized manner and proposes a Multi-Dimensional (MD) CAD model. The MD CAD model is composed of the MD CAD objects. The model can assist project planners in assessing information concerning the inter-relationships between schedule, cost, resources, and work areas. A computer implementation called MD-Construction Project Management Information System (MD-CPMIS) is presented to verify the feasibility of the proposed approach.