The progress of numerical control systems has been remarkable in many industries throughout the world, not least of all shipbuilding. Shipbuilders have long dreamt of ways of accomplishing complete automation in design and production and studies on numerical control systems are at last making this dream a reality. Hitachi Shipbuilding and Engineering Company have developed many types of softwares for use with numerical control systems, and have succeeded in organizing these for hull production design, thus with the aid of a digital computer are now able to fair ship lines, develop mould loft settings and prepare tapes as inputs for numerically controlled tools. Among softwares now in common use the most noteworthy is the auto programming system HIZAC (Hitachi-Zosen Auto Coding), which was developed for, and based upon the highly advanced shipbuilding techniques now used in Japan. This offers input paper tapes to the numercally controlled flamecutters and drafters by means of a digital computer from only a few design characteristics supplied by mould loftsmen, Details of numerical control systems and the software HIZAC are described in this paper, the lecture to be given at a meeting of the Society of Naval Architects of Japan.