Objective To retrospectively analyze the screening results of phenylketonuria(PKU ) among 567 691 neonates in Gansu Province to understand the prevalence situation of PKU and provide the basic data for preventing and treating PKU in Gansu Province .Methods 567 691 samples of neonatal dried heel blood spots were collected by Gansu Province Newborn Screening Cen‐ter from 2009 to 2014 and the phenylalanine (Phe) level was quantitatively determined by the fluorescence quantification method . The identification was performed by using the urine pterine profile analysis and phenylalanine hydroxylase(PAH) gene mutation de‐tection .Results Among 567 691 neonates ,166 neonates were diagnosed as PKU ,the total detection rate was 1/3 420 ,in which 119 cases (71 .7% ) were classic PKU ,33 cases (19 .9% ) were moderate PKU and 14 cases (8 .4% ) were mild PKU .Conclusion The morbidity rate of PKU in Gansu Province is much higher than the national average incidence level ,which is dominated by classic PKU .Therefore Gansu Province should become the major area of PKU prevention and treatment .