This study relates to a rule-based cutting condition recommendation system for the implementation of intelligent machine tools. For cutting processes, information on the configuration and material of the work-piece, machine tools, and other related tools are essential, similarly as machine tools operators determine appropriate cutting conditions using their own experience along with such details. The development of computer technology has enhanced the intelligence of machine tools, allowing them to automatically calculate and determine relevant cutting data. In this study, a rule-based cutting condition recommendation system is implemented and installed on an open controller for intelligent machine tools. The cutting conditions utilized were provided by tool-makers. The conditions were recommended by classification into high-speed and common speed machining. Efficiency and accuracy has been improved by the implemented system, which is expected to be a key technology for the development of intelligent machine tools.