Objective To analysis the family environment of children with hyperphenylalanenimia (HPA) and the psychological condition of their mothers,and seek better treatment options. Methods 39 children with hyperphenylalanenimia detected by neonatal screening in Qingdao were compared to 57 matched children.Family Environment Scale-Chinese Version(FES-CV) and Symptom Check List-90(SCL-90) were used to investigate the related factors of the two groups.Results 1)The conflict scores of FES-CV in HPA children were higher than those in controls while the scores of ethical-religion were lower than those in controls (P<0.05).The children with HPA was significantly higher than the control group in the organization scores (P<0.01).2)In the comparison of SCL-90 of the mothers,the scores of total score,total average marks,positive symptom item number,somatization,interpersonal relationships,depression and psychiatric factor in HPA children were higher than the controls,while the scores of negative symptom item number were lower than the controls (P<0.05).The children with HPA was significantly higher than the control group in compulsive symptoms(P<0.01).3)There was no significant differences in FES-CV and SCL-90 between HPA children with different compliance (P>0.05). Conclusion In the treatment of HPA children,psychological intervention to HPA children and their mothers could help to improve the therapeutic effect of the HPA children.