Abstract: In this paper, a robust real time lane departure warning system for safe driving assistant is proposed. The design of hardware and software is achieved by using an ALTERA CycloneⅡFPGA with on-chip NIOS Ⅱ system on it as the process core, a robust algorithm for quick lane departure warning is applied in the design, while the IP core is customized with Avalon bus. Test result shows that the accuracy and real-time performance of the system can meet the needs of lane departure warning all day.