A mobile communication device is a small size of portable computer which provides communication service. One of the biggest barriers in developing the mobile communication device is security. To protect itself against security threats, the mobile communication device need to be loaded with various kinds of security functions such as firewall, access control, and so on. However because the mobile communication device has relatively poor computing power and inconvenient user interface, it may experience performance deterioration and user inconveniency in case that it employs all the security functions. This paper proposes a context-aware dynamic security configuration scheme for effective security management of the mobile communication device. Our scheme can maximize the performance of the mobile communication device in terms of computing resource efficiency and user convenience without degrading security level by automatically optimizing its security configuration based on its security context. The performance of our scheme is measured and evaluated through experiments.