There is provided a marking method that is highly productive and enables production of easily-identifiable compositions for use in oral administration such as drugs and foods without damaging the quality of the oral composition. The marking method according to the present invention is a method for marking such a composition for use in oral administration and includes the steps of: dispersing a change in color-inducing oxide in the composition for use in oral administration and scanning a surface of the composition for use in oral administration with a laser beam at wavelengths of from 200 nm to 1100 nm and with from 0.1 W to 50 W average power in to make the particles of the change in color-inducing oxide agglomerate so as to become discolored. The change in color-inducing oxide used in the present invention is at least one selected from the group consisting of titanium dioxide, yellow ferric oxide, and red ferric oxide.
