Example embodiments pertain to an organic semiconductor composition, in which low-molecular-weight oligomer compounds are distributed in the spaces of a polymer compound so that the free spaces of the organic semiconductor polymer compound are filled with the low-molecular-weight oligomer compounds upon the formation of an organic semiconductor thin film, thereby increasing .pi.-.pi. stacking effects, and to an organic semiconductor thin film using the same and an organic electronic device employing the thin film. Using the organic semiconductor composition according to example embodiments, a semiconductor thin film and an organic electronic device having improved electrical properties may be manufactured.