This study was described squamation chronology and scale morphology of the bitterling, Acheilognathus yamatsutae. The first scale appeared on the caudal peduncle region at 11.4±0.18mm and the final squamation was completed at 16.5±0.34mm in standard length. The height of the scales on anterior region was longer than width of it and the height increased to predorsal region and decreased in posterior region. The largest scales were center of lateral line scales and the number of circuli in each scale increased proportionately to the height to scale. Regeneration scales were average 20.9% in lateral line, 3 rows of above the lateral line and 2 rows of below the lateral line scales. The scales below the lateral line were observed many regeneration scales than the scales above the lateral line.