The work aims to study preparation methods of novel surface microstructure. A special “columnar” microstructure surface was prepared on 304 stainless steel substrate by means of micro-arc spark deposition. Scanning electron microscope (SEM), optical microscope (OM) and hardness tester were applied to preliminary analysis of morphology, section features and microhardness of the micro-columns. Those micro-columns obtained by ESD were distributed separately and regularly at the distance of nearly 0.8~1.2 mm. Diameter of the micro-columns ranged from 300 to 500 μm. A further observation indicated that rivalrous behaviors were present in the growth between different micro-columns exhibiting typical overlapping characteristics and growing in stacked form. Seen from cross section of the micro-column, thickness of a single pulse deposition film was about 15~20 μm, and single layer in the micro-column was generally in a lenslike form (thick in the middle and thin on both sides). Average hardness of the deposited micro-columns was nearly 320HV, slightly lower than substrate strength near bonding interface (~340HV). Formation of such surfaces can be partly attributed to ESD technical features including single point and high frequency characteristics. The competing mechanism in discharge deposition directly leads to the formation of micro-columns.