Provided are a path control method, a wireless communication system, a path control device, and a non-transitory computer readable medium which are capable of securing efficient traffic accommodation, while maintaining communication quality. The path control method controls a communication path by selecting one path from among a plurality of path candidates with respect to a specific piece of traffic in a network constituted of a radio link provided with an adaptive modulation function. A requested band of the piece of traffic is compared with an allocatable band allocatable to a first path candidate that is included in the plurality of path candidates and that satisfies a degree of stability requested by the piece of traffic by a first modulation method. As a result of the comparison, when the requested band of the piece of traffic is larger than the allocatable band, a penalty cost due to transmission using a band usable by a second modulation method having a lower degree of stability is given to the first path candidate so that the first path candidate is less likely to be selected as compared with the other path candidates for selecting one path from among the plurality of path candidates.