Smartphones have become so necessary nowadays because of their services and features. They are similar to laptops and PCs; for that reason they faced security problems like virus, computation, storage and so on. Due to the resource restrictions of smartphone, cloud services are almost solving these problems. Cloud computing is internet based development and it is increase the capacity of client devices. Cloud services provides on demand, pay-as-you-go and utility computing. This paper discuss about cloud computing and security issues.