Abstract: With the fast development of the highway construction in China,there are usually approach slab fracture, bridgehead vehicle jump at the joint of road and bridge because of structure and feature, construction, rainfall and so on. It affects severely the operation of the high way. This study classify the effect of the backfills on abutment in to three types: the earth pressure behind abutment, differential settlement and the load result from soft roadbed sliding. This study has analyzed the cause of them, quantization indexes and research survey of them.