Objective National external quality assessment (EQA) results from 2005 to 2008 for HLA class Ⅰ (A, B) and class Ⅱ (DRB1) low-resolution DNA typing were summarized with the goal of exploring strategies to assure and improve HLA DNA typing performance in clinical testing. Methods HLA allele results from the four consecutive years EQA events were analysed. Different kinds of errors were described and classified, and the possible causes were discussed. Results Participant laboratories were increasing in the four consecutive years with the number of 22, 28, 47 and 61 in 2005, 2006, 2007 and 2008,respectively. 2 844 HLA DNA typings were returned from the participants during the 4 years EQA surveys, and overall 30 errors (1.05%) were identified. These 30 errors were classified into two major types of errors including 25 technical genotyping errors and 5 human errors. The proportion of laboratory participants which made mistakes was 13. 6%, 10. 7%, 10. 6% and 16.4% in 2005, 2006, 2007 and 2008, respectively. Conclusions Above 10% of participant laboratories exhibited errors in the four consecutive years HLA molecular typing EQA surveys. Relevant important attentions should be greatly paid to clinical HLA molecular typing test.