The study describes a new NC data generation method for 5-axis control machining, using curved interpolation. In conventional linear interpolation, the amount of NC data tends to increase with increasing the geometrical accuracy of workpiece configurations, which often leads to the reduction in feed speed of machine tools, especially for 5-axis control machining, since a huge amount of NC data can not be accepted in time. On the contrary, as the curved interpolation requires only a few parameters to express workpiece configurations, NC data can be transmitted rapidly, compared with the conventional linear interpolation. The curved interpolation was already applied successfully to 3-axis control machining, however not to 5-axis control one. Thus, in the study, 5-dimensional non-uniform B-spline curve is employed to express 5-axis control curved interpolation NC data in terms of NC data reduction, using 5-axis control collision-free NC data. In a 5-dimensional non-uniform B-spline curve, NC data are significantly compressed by appropriately selecting knot vector on the basis of equally divided curvature area method. From the experimental results of 5-axis control machining, it is confirmed that the curved interpolation has the potential of reducing large amount of NC data without deteriorating the surface roughness and shape accuracy of workpieces.