To provide a road heating system having a high efficiency by minimizing the running cost while reducing its environmental load.

This road heating system 1 comprises a first heat exchange medium passage 3 installed to an area 2 whereto solar light is radiated, its one end 5b is laid underground and connected to one end 3b of a second heat exchange medium passage 5 in an area 4 which is not radiated by the solar light, another end 3a of the first heat exchange medium passage and another end 5a of the second heat exchange medium passage are connected together by a third heat exchange medium passage 7; and a medium-sending pressure pump 8 for circulating the heat exchange medium from the first heat exchange medium passage 3 to the second heat exchange medium passage 5 is installed through the third heat exchange medium passage 7.