Freeform surfaces are widely used in various industries. However, they require much time to be machined because of complicated geometry. To increase machining productivity, partitioning methods for freeform surface have been proposed by several previous studies regarding selection of cutting tools and tool-path. This paper proposes a new partitioning method based on Gaussian and mean curvatures to define boundaries of local patches using Freeman algorithm. Simulation results with a B-Spline surface show that the proposed method combined with cutting tool selection strategies can reduce machining time and surface roughness when compared with the non-partitioned method.