Objective: Study the effect of leukocyte-depleted before blood preservation on blood quality. Methods: Collected whole blood 30 bags from healthy donors by using single-used leukocyte-depleted blood taking bags (size 200ml), depleted leukocytes in 6 hours, and centrifuged to remove plasma , prepared the whole blood into RBC suspension. Then preserved in 4℃. Collected blood samples from the whole blood which before and after leukocyte-depleted, detected the counting of RBC and WBC, free hemoglobin(FHb),lactate dehydrogenase(LDH), K+ and the volume; calculated erythrocyte recovery and leukocyte removal efficiency. Preserved 10 bags in 4℃ for 35 days, then calculated FHb, LDH and K+, and compared with RBC suspension which had not depleted leukocyte and had preserved 35 days in same conditions. Results: Erythrocyte recovery=(87.74±2.42)%, Eeukocyte removal efficiency= (97.59±1.47)%. There was no significant different of FHb between before and after leukocyte-depleted (P>0.05). After leukocyte-depleted LDH has significantly decreased (P<0.01), but K+ has significantly increased (P<0.01). After 35 days’ preserved, There was no significant different of K+ between leukocyte-depleted RBC and RBC suspension. FHb of leukocyte-depleted RBC were slightly higher than control cohorts (P<0.05), and LDH were significantly lower than control cohorts (P<0.01). Conclusion: Maybe process of leukocyte-depleted before blood preservation shall slightly scathes the RBC. But it is beneficial to RBC preservation and transfusion safety, and more suitable for clinical use especially patient who suffer from leukemia.