Mobile Cloud Computing Architecture, Application Model, and Challenging Issues In the era of this growing technology, Mobile Cloud Computing (MCC) has become a major discussion thread for transforming the internet computing infrastructure. For IT world, MCC provides a vast platform where mobile users can explore their data anywhere anytime using Cloud services. MobileCloud Computing integrates the advantage of cloud computing, internet technology and mobilecomputing. That facilitates it to become more users friendly to store their data at cloud with a great ease. Despite a lot of advancement is achieved by the MCC, but still it is below the user expectations due to privacy and security issues of the regulated data. Significantly the thrust of the research is focused on exterminating various critical issues of MCC to make it more reliable and secure. In order to better understand the challenging issues, we have surveyed the existing work and classify the various application models in new perspective of used operating platform.