Large amount of In-rich fibers are found on combinatorial deposited In-Y thin film. Sizes, morphologies, and distributions of fibers are most likely dependent on the film composition. Oxidation of the film seems to play an important role for the spontaneous formation of fibers. Demonstrate a potential application of combinatorial method to study fibers. Open a possibility for novel synthesis technique of one dimensional nanostructured materials. The results presented could be utilized as a new synthesis technique for one-dimensional nanostructured materials. The SEM results improve the direct and spontaneous formation of In micro-and nano-fibers.