To provide a canister mounting structure of a motorcycle which improves riding feeling of a fellow passenger, and secures high security with respect to the canister.

The canister mounting structure includes: a rear cowl 26 covering a seat rail 14 constituting the rear part of a vehicle frame; and the canister 35 which sucks evaporating gas in a fuel tank 18 arranged on a front upper side of the vehicle frame. The seat rail 14 has an inward part 14a for reducing the width dimension. The canister 35 is mounted inside of the rear cowl 26 in the rear side rather than a front end 14b of the inward part 14a.