α-Galactosidase A (α-Gal A ) activities in plasma and peripheral blood granulocytes of 100healthy subjects and one patient with Fabry disease was determined by means of fluorogenic substrate.The results showed that the enzymatic activities of peripheral blood granulocytes and plasma in 100 subjects were (51.97 ± 15.24)and(148.08±26.30) nmol · h-1 · ml-1 respectively.The α-Gal A activities in plasma and granulocytes were positively correlated( r=0.533,P＜0.01 ).The enzymatic activities in peripheral blood granulocytes and plasma of the patients with Fabry disease were 1.05 and 10.06 nmol · h-1 · ml-1 respectively,both much lower than those of 100healthy subjects.These results suggest that α-Gal A activity in plasma and peripheral blood granulocytes can be used for diagnosis and screening of Fabry disease.