The present invention relates to air duct air filter system for a vehicle equipped with an air filter of a roll and is arranged so that as a box shape with a hollow inside, has a respective air inlet and an air outlet at the opposite side air duct of the vehicle to be communicated to the connected housing; Roll form that both ends of which are each pay-off reel, and is manufactured in the form of a roll wound with a sense gimril, in association with the rotation of the sense gilril built enables the transfer operation in a state of being in close contact across at right angles to the inner end of the air inlet of the housing the air filter; First drive means for the magnetic sensitive member is possible to connect the power transmission gimril rotate the alternate winding gimril to the cold sense gimril by a predetermined length of the air filter and; Driving the first drive means each time it reaches the first drive means and the vehicle control unit and each electrically coupled to a predetermined vehicle cumulative distance traveled winding the filter section contamination by rotating the sense gimril of the air filter in a sense gimril removed from the setting position, it characterized in that the filter section constituting the new transferred unwound from the pay-off reel to the control unit for setting in the setting position.