One of the methods designed by author for measuring resolution printed on paper or media from printer in which the pattern is formed by dots is described in this paper. This particular method printed out a special doted pattern by the testing printer and captured the image pattern through optical microscope with the integration of CCD CAMERA to process the image captured via image processing software. Several sets of dual dots distance were calculated and analyzed to come up with the printing resolution, not by the print head or optical scan module.This method is suitable for testing any printing resolution that forms pattern with dots. The measuring method involves of a simple pattern design: two dots are separated and isolated at a proper distance, with the drafting software or control device to design a suitable diameter of a dot and gradually increase the distance between the center of the two dots, the increased value is less than the length of the resolution, increase the total length at least more than multiple times the testing resolution. Use this same method to print out several sets of patterns with perpendicular in horizontal and vertical axis respectively and capture the pattern from the combination of appropriate microscope and CCD zoom factor. Calculating the geometric center of the distance for the two points through the image processing software and from the compile statistics of the measured distances to come to know the distance change between horizontal and vertical axis would be the length of the printer resolution.