RESUMO
Objective To discuss clinical significance of the neutrophil alkaline phosphatase(NAP) activity in polycythemia pa‐tients .Methods 35 cases of patients with secondary polycythemia(secondary group) and 22 patients with polycythemia vera (poly‐cythemia vera group) were enrolled in the study ,whose peripheral blood smears were stained by using chemical method and the pos‐itive rate and scores of NAP were assessed .In addition to that ,30 cases of healthy people who had underwent physical examination were recruited as control group .Results NAP positive rate and scores of the polycythemia vera group were significantly higher than those of secondary and control group(P0 .05) .Conclusion NAP score is a good methord to diagnose polycythemia ,which could facilitate rapid ,accurate diagno‐sis and be used as auxiliary indicators in the differential diagnosis of polycythemia .