The rise of mobility has witnessed a skyrocket of the number of mobile devices users. Smart phone is almost a must-have for most young adult in today’s society and therefore mobile security is a hot topic issue. The global smartphone shipments have been reported to hit 230 million devices in the second quarter of 2013 with a growth of 47 percent, among which Android operation system captured a record of 80 percent market share. However, along with the popularity, cyber threats increase as well. Due to its high market share and open source architecture, Android has become the most vulnerable mobile operating system to security attacks. Types of security threats such as simple text message Trojans to a more sophisticated rootkits are surfacing every day. In order to seek solutions to Android Security, this paper will begin with the discussion of Android features and characteristics. Then in-depth insights into Android’s system architecture, Play store, and apps etc. will be researched and discussed and finally via analysis this paper will attempt to give feasible solutions to improve Android’s security model from the user’s awareness level as well as technical level.