In tool-path generation process for 5-axis face milling, the specification of cutter posture is one of the critical issues that contribute to the computation load. In this paper, a quick algorithm is presented to specify the cutter posture at a surface point based on the cutters accessibility maps (A-maps) at all the sampled points, obtained during cutter selection. Integrated with this quick algorithm, an efficient approach is proposed to generate a set of iso-planar tool-paths for finishing a given surface withmaximum machining efficiency without violating the desirable profile and scallop height tolerance. One example is given to confirm the validity of the quick algorithm for cutter posture and the efficiency of the algorithm for tool-path generation.