Objective To establish a PCR-RFLP method for detection of CD26 mutation of hemoglobin E(HbE)gene.Methods The genome DNA from the family members who were suspected of having HbE combined with beta-thalassemia was amplified using PCR.The PCR products were digested by restriction endonuclease Mnl I,and then separated on PAGE.The electrophoretical patterns were finally analyzed to confirm if CD26 mutation was present or not.Results Four cases with CD26 mutation in two families were successfully screened out.Conclusion Although the incident frequency of CD26 mutation in Sichuan population is not high,it must not be neglected since it may present alone or combined with other type of thalassemia.PCR-RFLP method described in this study is available in screening mutated HbE gene and treating the disease owing to its simplicity,rapidity and specificity.