A simple ion irradiation technique to generate the positive and negative patterns of PMMA/Alq3 was demonstrated. The thin PMMA films containing various amounts of Alq3 prepared by spin-coating on a substrate were irradiated by accelerated proton ions through a pattern mask under various conditions. The SEM observation showed that the positive and negative patterns of the thin films were formed at fluences below 1 X 10^(15) and above 1 x lO^(16) ions/cm2 respectivel y. Furthermore. it was clearly seen from the fluorescence images for the formed patterns that the positive PMMA/Alq3 patterns were visible but the negative patterns were not so due to the destruction of the AIq3 molecules caused by the ion irradiation.