Abstract: The fabrication of microfluidic chips by UV-LIGA process with the large ratio of line space to line width was studied.The process of large area exposure of SU8 was optimized for the micro-electroforming;a novel non-planar micro-electroforming method was developed for the large ratio of line space to line width.The results indicate that this new micro-electroforming technique will enable the mass fabrication of microfluidic chips by UV-LIGA process.