In this paper, a concurrent object-oriented programming model is presented. It consists of a group of concurrent objects which may have bodies. When the concurrent object with a body is created, its body begin to run. In this model, the synchronous message passing is adopted for inter-object communication and the intra-object concurrency is permitted. The object concurrency control is distributed among each method's activation condition in an object. Based on the presented model, C++ is extended. A policy is also given to transform the classes defined in the extended C++ into C++ classes. The implementation uses the multithreading and synchronization mechanisms supported in some multitasking operating systems, such as Windows 95.