n order to generate the program for fabricating complicated rotation surfaces, an automatic program software for Computer Numerical Control （CNC） turning machine is developed using QT4.8 on Windows platform. A new method for mathematically presenting the rotational surfaces was proposed with the generatrix (or contour line), considering the features of the rotational surfaces. The software was achieved of the following functions:(1)describing the generatix (or contour line) by smoothing the joints of multi-curves; (2)generating the tool path， and calculating coordinates of path node by the equal-error approaching method; (3)releasing the CNC program considering the characteristics of the CNC system. Feasibility of the software is verified based on the experimental results.