Mold industry market has been demanding higher quality and shortening manufacturing time. Those demands will be intensifying in the future. In these market circumstances, NC machine cutting processes should be improved to innovational ways for satisfactory of the mold industry market and improvement of competitiveness. NC cutting of the mold manufacturing takes the main portion of time and money. But there are many difficulties about the NC machining. Machining time and finishing quality come out differently according to CAM data quality and machine operator ' s skill. Operating NC machine can not progress fluently for lacking of the cutting information. Therefore, it is hard to expect to reducing error rate, and it can ' t get to maximize productivity through ATC (Automatic Tool Change) unmanned operating. NC Brain solves all those difficulties by CNC machining simulation. During simulation, NC Brain regenerates CAM data into much optimized NC data practically. It makes a NC machine to perform higher productivity, and workshop floor can be change to be better environment by stress less machine operation. NC Brain will be the best system for Improvement productivity and equipping distinguished technologies by Cutting Technique upward Standardization.