Abstract: An interchange system serving elevated railways and roadways intersecting each other, which system comprises a rotary possessing of a cylindrical plaza at the center thereof and an annular bus stop compound along the periphery of the plaza, a railcar platform above the rotary, interconnecting passages between the plaza, the bus stop compound and the railcar platform and tunnel-like passages dug across under the rotary to reduce a difference between the levels of the plaza and pedestrian paths formed along the opposite sides of the roadways, thereby to ensure the safety and convenience of pedestrians.