Compared to reticulocyte counting method of Sysmex R-3000 with manual counting method for 140 samples which requested test in clinical laboratory. Results are followed; R-3000 reproductibility has been measured 0.065 SD and 2.7 % CV by Q. C. material(reti-check). The reproductibility of R-3000 has very good value. The correlation coefficent of Sysmex R-3000 and manual reticulocyte counting method have 0.89, which has represented relatively good value.