In this study, a Mobile system is developed to retrieve image and ECG based DICOM files from the Cloud PACS System, and then redirect these files into the mobile based medical image viewing device which is built under the regulation of HTML5 on the Google Chrome browser. Physicians can query DICOM files, and view image ECG on this developed web system. Physicians can measure, zoom in/out, and adjust the brightness through this web platform. Because of the system is built under the regulation of HTML5, it breaks the limitation of different platforms such as iOS and Android. By making use of the advantages, such as portable and low cost, physicians can diagnose DICOM files more timely, and effective.