Abstract: Objective To avoid to send wrong test reports,we screen and ascertain suggestive parameter of cold agglutination in specimens of blood routine. Methods The specimen of cold agglutinin was tested immediate by the sysmex XE-2100,at the same time,make the physiological salt solution smear（PSSS） to observe RBC's modality under the microscope. Results Various RBC conglomeration can be found under microscope in all the specimen of cold agglutinin PSSS with MCH,MCHC prominent increased（MCH>33 pg,MCHC>380 g/L）,RBC prominent decreased in blood routine report. Conclusion MCH,MCHC prominent increased and RBC prominent decreased were the suggestive parameter in blood routine of cold agglutination specimens.

Key words: Cold agglutination, Blood routine, Parameter