【Objective】 To identify the main unqualified items in the external audit of blood station quality management system (referred to as external audit), in order to take necessary measures to continuously improve the quality system. 【Methods】 Unqualified items(data) in the national and Shandong provincial blood safety technical audits (referred to as national and provincial audits) and four blood station blood safety technical joint audits (referred to as inter station mutual audits) from 2017 to 2019 were collected and analyzed by Excel and Pareto curves (graphs). Corresponding corrective and preventive measures were developed and implemented, and then tracked and evaluated by the quality management department three months after the external audit to verify their effectiveness. 【Results】 In a total of 7 external audits of blood station quality management system that our blood station has participated in over the past 3 years (including 2 national audits, 2 provincial audits, and 3 inter station mutual audits), the main unqualified terms were "12 monitoring and continuous improvement" 11.90% (15/126), "13 blood donation services" 11.90% (15/126), "06 equipment" 10.32% (13/126), "11 records" 10.32% (13/126), "03 organization and personnel" 8.73% (11/126), "15 blood preparation" 7.94% (10/126), "08 safety and health" 7.14% (9/126), and "14 blood testing" 7.14% (9/126). Among them, "monitoring and continuous improvement" ranked first in two national audits and two provincial audits, with 16.67% (5/30) and 14.71% (5/34), respectively, and was 8.06% (5/62) in inter station mutual audit, and the difference between the three kinds of audits was not statistically significant (P>0.05). "Records" accounted the highest proportion in inter station mutual review of 19.35% (12/62), while was respectively 0 and 2.94% (1/34) in national and provincial audits, with statistically significant difference between the three kinds of audits (P<0.05). 【Conclusion】 External audit against unqualified items is important for quality improvement. By analyzing the unqualified terms, taking corresponding measures to improve weak links, and evaluating the effectiveness of those measures, it can effectively ensure the effective operation of blood station quality management system.