This paper deals with an off-line Japanese signature verification using a pattern matching method. An annoying problem encountered in off-line signature verification using a pattern matching is that variation of signature stroke widths and a registered signature selected from a set of reference samples affect the verification performance. In this paper, we propose a modified pattern matching method, which is independent of stroke widths, and an appropriate selection method of a registered signature to solve this problem. These methods were experimentally compared with a conventional pattern matching method and a random selection method of a registered signature. Experimental results showed that the proposed methods improve the verification performance.