Cloud robotic system is a mono- or multi- robot system that profits one or more services of Cloud Computing. In a few short years, Cloud robotics as a newly emerged field has already received much research and industrial attention. The use of the Cloud for robotics and automation brings some potential benefits largely ameliorating the performance of robotic systems. However, there are also some challenges. First of all, from the viewpoint of architecture, how to model and describe the architectures of Cloud robotic systems? How to deploy these architectures in Clouds? Merely a language could explicitly describe or model the architecture of Cloud robotic systems. In this paper, we present an architecture approach to support design and implementation of Cloud robotic system.