In order to accomplish collaborative product development in the area of engineering, a work platform is needed to support all-sided collaborative work by the different development partners at geographically different locations. The platform is established on the basis of a three-tier architecture which provides four advantages over Client/Sever model. First of all, it can improve the capability and scalability of the development system. Secondly it can enhance the functional reliability. Thirdly it can transfer main management works to application servers to reduce the overall expenses. Finally it can increase the feasibility and development efficiency. In a typical Collaborative Product Development (CPD) scenario, design work is always over emphasized, while expert supervision is paid little attention. So, it is necessary to build the CPD platform for design and evaluation by Computer-Supported Cooperative Work (CSCW) technology and the Internet technology. This paper introduces the system functions, benefits and further challenges. Then key technologies, such as concurrency control mechanism, shared whiteboard collaborative control strategy, are analyzed in detail. It is proved that the system helps to enhance the product development efficiency.