Recently, resolutions of printing devices are increased rapidly. Obviously, higher density makes better quality for any type of print. In regard thermal printing technology, highest density of mass production printhead is 600dpi except for the particular application of higher density than 600dpi with small quantity. To search the possibility of much higher density by thermal printing method, Kyocera developed 2400dpi and 4800dpi thermal printhead, and made printouts successfully. Printouts by those ultra high density thermal printhead are too small to see by naked eyes. Microscope is required to see it. The other hand, there are issues to solve as thermal printing with this ultra high density. In this paper, future possibility and issues of ultra high resolution thermal printing are introduced. Also the new potential application will be discussed.