A tool path generation method for generating a second tool path by performing a smoothing process on a first tool path for processing a work with a machine tool includes a change rate calculation step of calculating a curvature change rate of the first tool path at a plurality of moving points (P.sub.n) of the first tool path. The tool path generation method includes: a weight calculation step of calculating a moving average weight on the basis of the curvature change rate of the first tool path at each of the moving points (P.sub.n); and a step of calculating coordinate values of the moving average of the moving points (P.sub.n) using the weight at each of the moving points (P.sub.n), and setting the coordinate values of the moving average of the moving points (P.sub.n) as moving points of the second tool path.

A tool path generation method for generating a second tool path by performing a smoothing process on a first tool path for processing a work with a machine tool includes a change rate calculation step of calculating a curvature change rate of the first tool path at a plurality of moving points (P.sub.n) of the first tool path. The tool path generation method includes: a weight calculation step of calculating a moving average weight on the basis of the curvature change rate of the first tool path at each of the moving points (P.sub.n); and a step of calculating coordinate values of the moving average of the moving points (P.sub.n) using the weight at each of the moving points (P.sub.n), and setting the coordinate values of the moving average of the moving points (P.sub.n) as moving points of the second tool path.