This paper proposes a new integrated CAD system and a system model which uses a feature based CSG/ B rep mixed modeling algorithm, the model can describe and organize various design information and design processes for the whole architectural design procedure. 为了支持建筑设计全过程集成CAD系统,创建能够描述和组织建筑设计全过程中各种设计信息和各项设计活动的系统模型,提出了一种基于特征的CSG/B-rep混合建模方法。