【Objective】 To investigate the effect of cold agglutination on blood group typing. 【Methods】 37℃ water bath, absorption elution test and 2-mercaptoethanol method were used to eliminate the influence of cold agglutination. Forward and reverse blood group typing, cross matching, DAT and IAT experiments were then performed on red blood cells and serum after treatment. 【Results】 Before treatment, obvious discrepancy in forward /reverse typing and nontypable cross matching in 16 blood samples were noticed due to cold agglutination. After corresponding treatments, all samples were consistent or negative in forward/reverse typing, cross matching and antibody screening. No adverse reactions to cross matching blood transfusion occurred in patients, and the increase of hemoglobin was in line with the effective standard of transfusion. 【Conclusion】 37℃ water bath, absorption elution test and 2-mercaptoethanol method can be used to eliminate the interference caused by cold agglutination to obtain correct typing results. The strong reactivity caused by cold agglutination in AIHA patients were different from other cases, which deserved our attention.