Objective To investigate the incidence and diagnosis of glucose-6-phosphate dehydrogenate(G-6-PD) deficiency through screening with umbilical blood or infants' peripheral blood.Methods The umbilical blood of 11574 infants delivered in our hospital was detected to screen G-6-PD deficiency.Activity of G-6-PD was also detected in 320 G-6-PD deficiency infants and 215 normal infants from 3 to 5 years old.Results Six hundred and forty-one patients in 11574 cases were screened with umbilical blood as G-6-PD deficiency and the incidence rate was 5.5%.The incidence rates in boys and girls were 7.9% and 3.0% respectively with significant difference(P