Inspired by significant progress in cloud computing technology, a range of applications are increasingly being offered to customers based on cloud servers. In this paper, we design a moving object detection system that enables clients to forward video captured on mobile devices to a server in the cloud. Within the cloud, the video begins to be processed with the moving object in the video detected by the cloud sever. This system enables utilization of the computing ability of the cloud platform and avoids having to rely on the limited processing capacity of mobile devices. As a result, this architecture significantly expands the scope of application for moving object detection.