To solve the problems existing in the OSEK operating systems, such as low real-time performance and efficiency, this thesis proposes a new OSEK operating system, namely, MiniOSEK, which is built on the servent/exe-flow model, and in accordance with the OSEK/VDX standard. The design idea of MiniOSEK is introduce message-driven idea into OSEK operating system. When a task needs to call an API function which conform OSEK OS standard, it just needs to send a message to this API function. In this way, the time required for context switch can be shortened and the real-time of the embedded system can be improved.