We demonstrate a highly compact third-order elliptical micro-ring add-drop filter based on a silicon-on-insulator wafer.The elliptical micro-ring resonator has a major radius of 6μm (minor radius of 4.112μm) and a large free spectral range of 18nm.Experimental results show a box-like channel dropping response,which has a 3dB bandwidth of ～2.7nm,high out-of-band signal rejection of around 40dB and a very low drop loss (＜0.5dB).Simulation agrees well with the experiments.The footprint of the whole chip is only 0.0003mm2.