Most current part libraries are created and deployed in speci c usage environments or CAD platforms, which inevitably brings obstacles in the share and exchange for part information. To reduce repeated development and provide a uniform interface for designers in different sites, a 3D part library in cloud scheme is presented in this paper. Host programs with predetermined speci cation can access the part data through an adapter according to their customized requests with uniform interfaces, which constructs a ubiquitous service. To realize host independence, the part models are created in a native ACIS modeler, and then they are converted into 3D les in various formats for practical needs, nally these les are imported into CAD systems or other platforms in real designs. The whole framework can be divided into three components, namely, PLS(Part Library Service) provider, PLS adapters and hosts. PLS provider is the kernel of 3D data access service in cloud scheme, while PLS adapters serve as the bridges that connect PLS provider and hosts, and the PLS can be grafted on various applications including current mainstream CAD systems as a plug-in module or run on the websites or even mobile terminals. The PLS provider is deployed and maintained on cloud and users can acquire remote part information within a local ongoing project. In the detailed construction of this part library, diversiform knowledge for part parameters and structures is implanted to de ne the geometry and rule constraints in the 3D modeling, with which the backstage has the ability of conveniently editing the information in the part library for better upgrade and contrapuntally services. The concept has been implemented within a PaaS framework to provide the ubiquitous 3D part data access, which has been successfully applied in a large number of manufacturing enterprises, and accumulates considerable practical cases.