Provided is compound for improving blood flow at sites of impaired circulation in the extremities, through promoting development of collateral blood circulation without angiogenesis also provided is a therapeutic agent for sensitivity to cold or cold sensation, in which the active ingredient is a compound for improving blood flow at sites of impaired circulation in the extremities. A collateral blood flow development promoter, in which the active ingredient is (-)-6-[3-[3-cyclopropyl-3-[(1R,2R)-2-hydroxycyclohexyl]ureido]propoxy]-2(1H)-quinolinone or a salt thereof, or a solvate thereof.
