Disclosed is a canister for a vehicle having an auxiliary canister, which includes: a main canister that has an inlet and an outlet formed therein, an evaporation gas being introduced into the main canister through the inlet from a fuel tank and the evaporation gas introduced through the inlet being discharged through the outlet to the intake side of an engine when the engine is driven, and has a trapping member therein; and an auxiliary canister that is installed to communicate with the main canister to allow external air to be introduced into the main canister or to allow the evaporation gas to flow when the engine is turned off, and has a second trapping member therein, wherein the auxiliary canister includes the second trapping member therein, which has a plurality of pores in the form of a honeycomb.