With the development of expressway in China, the protection of expressway side slopes changes from the traditional masonry protection to the ecologyfavorable vegetation protection. The application of side slope vegetation protection can not only eliminate the adverse effect on the environment imposed by expressways, minimize the regional water/soil loss,but also can achieve a sustainable and harmonic development between the expressways and the landscapes. In the paper, seed spraying technology, one of the vegetation protection technologies adopted on BiTong expressway, is presented in respect of working principle, mechanical equipment, materials and execution workmanship. The application conditions, vegetation types, matching plan and execution workmanship of the seed spraying technology are summarized on basis of studies on the natural environment conditions along BiTong expressway, including climate, soil, vegetation and engineering conditions. Furthermore, improvement suggestions are made for the seed spraying technology in respect of design and execution.