To provide a method for snow removal and chemical-sprinkling assist and its system capable of efficiently carrying out road management works such as snow removal and chemical by sprinkling accurately and easily grasping a longitudinal road surface temperature distribution.

The underground temperature under a road 2 is measured by an optical fiber cable 3 embedded in the longitudinal direction of the road 2. From the longitudinal road 2 face temperature obtained by use of the underground temperature under the road 2 and the underground thermal constant such as the thermal conductivity, thermal capacity, etc., under the road and information of meteorological sensors 4 comprising thermometers, rain gauge and snow gauge set at a plurality of positions, the start time, stop time, execution place of snow removal and chemical-sprinkling are estimated, and the information is provided to the road manager to assist the manager.