Well-structured design knowledge is crucial to Design for Mass Customization (DFMC). It is a formidable challenge to tackle various structures and meaning Chinese semi-structural design knowledge. Chinese text description is a notable data characteristic when analyzing the knowledge requirements of DFMC. A knowledge management system architecture is proposed based on a relational database server cooperating with a Chinese full text database server. Grounding on Chinese semantics, the system functions are implemented which include knowledge representation, knowledge acquisition, knowledge reasoning, and knowledge service and system management. With the intelligent processing and service of design knowledge based on Chinese semantics, the construction of the knowledge management system for DFMC facilitates product development.