We propose the analysis method of spur mark distance for discrimination of inkjet printers using a measuring microscope. The conventional method is the measurement of the pitch and the mutual distance of the spur marks which depend on the model of inkjet printers. Therefore, it is difficult to discriminate the same models of inkjet printers by the conventional method. First, we established the analysis method to obtain the spur mark distance indented by one rotation of spur gear and examined the difference of the distances in a printer using correlation coefficients. Next, we applied this method to discriminate 60 inkjet printers of the same model. As a result, the correlation coefficients between the same printers approximated to 1. On the other hand, the correlation coefficients between the different printers were widely distributed in the range from –1 to 1. These results indicate that our proposed method can distinguish printers of the same model and be a useful tool for discrimination of printers in combination with the conventional method.