UV-LIGA technology was investigated to fabricate the ultra-high micro electrode array, and the micro electrochemical machining was used as an aided method to remove the SU-8 resist.During the lithography process,a SU-8 mold up to 1 mm thick was fabricated on the substrate by methods of single coating,increasing soft bake temperature and decreasing post bake temperature.Before the electroforming process, a reverse polarity procedure was carried out to make the micro roots on the substrate, which could enhance the adhesion of the electroformed micro copper electrode array to the substrate.Using the optimized parameters: single coating; soft bake 110 ℃/12 h; post bake 50 ℃/5 min, 70 ℃/10 min, 90 ℃/30 min; electrochemcial machining 10 V/15 min et al., the micro electrode arrays with a heigh of 900 μm and a linewidth of 300 μm were fabricated.The result indicates that UV-LIGA is an excellent method for fabricating ultra-high metal micro electrode arrays.