The present invention provides a pharmaceutical composition for prophylaxis and treatment of NAFLD comprising as an active ingredient a 1,4-benzoxazine compound represented by formula (I): or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, as well as a method for prophylaxis and treatment of NAFLD which comprises administering a therapeutically effective amount of the above-mentioned 1,4-benzoxazine compound represented by formula (I) and so on to a patient in need thereof.