Provided is a method for calculating a scanning pattern of light and an optical scanning apparatus. The method includes the steps of: detecting a resonance frequency and an attenuation coefficient of an oscillation part of an optical fiber which guides light from a light source and irradiates an object with the light; and calculating a scanning pattern of the light, based on the detected resonance frequency and attenuation coefficient. The apparatus includes: an optical fiber which guides light from a light source and irradiates an object with the light; a scanning part which drives an oscillation part oscillatably supported of the optical fiber; a detector which detects a resonance frequency of the oscillation part; a calculation part which determines an irradiation position of the light using a scanning pattern calculated based on the resonance frequency detected by the detector and the attenuation coefficient obtained in advance.