Random bead microarray in which each bead has been functionalized with different biomolecules are of great interest. The process by which one would identify the location of each bead is referred to as decoding. The decoding step has played a challenging role in microarray technologies due to the increase in complexity with the increase in array size. Here we report a novel, fast and reliable method of decoding randomly assembled arrays based on polymer beads with unique spectroscopic signatures. Beads were synthesized by dispersion polymerization of a family of styrene monomers and methacrylic acid to generate a spectroscopically encoded bead library. In addition to identifying the self-encoded beads through their unique spectrum in a tetraplex experiment, Raman spectroscopy was used to monitor antibody-antigen binding events on the barcoded beads. The simplicity, versatility and rapid analysis enabled by this self-encoded bead array platform technology demonstrates its potential in high-throughput biomolecular multiplex screening.