Abstract: Objective To compare the difference of quality of concentrated platelet prepared by white film with two methods of blood bag. Methods Totally 40 pieces of 400 mL ACD anticoagulant whole blood were collected and shaken well. After setting for 1 hour, the blood samples were evenly divided into top-bottom blood bag and quadruplet blood bag, with 200 mL whole blood in each bag. The top-bottom blood bag was selected as experimental group, and the quadruplet blood bag was selected as control group. Platelet concentrate was purified by the G5 Automatic Blood Component Processing System. Results The platelets were(986.0±277.0)×10⁹/L in the experimental group and(705.0±322.0)×10⁹/L in the control group, and there was significant difference between two groups(P<0.01). There were no significant differences in the content of plasma and the contents of residual red blood cells, platelets, white blood cells and hemoglobin in plasma between two groups(P>0.05). Conclusion The quantity and quality of platelet concentrate as well as the reclamation rate of red blood cells prepared by the top-bottom blood bag are better than those by the quadruplet blood bags.