Geographic information processing and visualization on new types of platform such as mobile environment or web environment has been regarded as one of industrial and academic issues. For this, the various approaches for mobile GIS and Web GIS are being carried out on the application level. Motivation of this study is on system architecture and a prototype implementation for 3D mobile and Web 3D application. Platforms and devices for mobile 3D GIS technology manipulating geographic data and information provide some limitation to design and implement: limited CPU and memory, absence or limited performance of graphic accelerators, small size of display panel, and so on. Moreover, in the urban application, 3D spatial information is crucial for complex feature modeling. Core functions of mobile 3D GIS by feature-based approach was designed as some modules: data model and design of spatial features, editing and manipulating of 3D landscape objects, generating of geometrically complex type features, supporting of both database and file system, handling of attributes for 3D objects, texture mapping of complex types of 3D objects and digital elevation model with image library containing high resolution satellite imagery. With these functions, an integrated urban 3D modeling and rendering system was implemented using standard mobile 3D graphic API (application programming interface), OPENGL|ES (Open GL for embedded system), with MS EVC 4.0 MFC. As well as this mobile 3D design and implementation, multiple types of geographic features or objects encoded by GML (geography markup language) for the XML-databases building are taken into account of practical applicability for 3D urban approaches. For this process, it was carried out to implement GML editor software with the main functions: supporting and customizing map style sheet, attribute editing, adding/deleting/manipulating geo-base features in fundamental urban data model as the framework model level and user-defined model f- - or database extension, Web publishing through general web browser, and importing/exporting ESRI-shape file format and data transferring to SVG (scalable vector graphics) for 2D transportation features and X3D (extensible Web 3D) for 3D complex features. These two implementations such as mobile 3D and web 3D can be easily linked in data communication and sharing for the 3D urban modeling dealing with complex types of multiple features on integrated architecture.