Objective To investigate the influence of feeding behavior of parents on the blood phenylalanine (Phe) concentration and deterioration quotient (DQ) of children with phenylketonuria(PKU). Methods Totally 49 cases of classic PKU children and their long-term following parents were chosen,who were diagnosed by newborn screening center of Taian between January 2000 to May 2010 and continued insurance treatment for six years(28 boys,21 girls;parents:father 9 cases and mother 40 cases).The dietary feeding behavior of parents was investigated by a self-made questionnaire and analyzed by single factor analysis of variance and multiple stepwise regression analysis. Results The multiple stepwise regression analysis of 26 items were carried out,high protein diet,tend to high protein diet behavior,food preparation(food pattern,whether parence cook dinner for the children specially),had significant influence on the blood Phe concentration and DQ (P＜0.05). Conclusion The feeding behaviors of parents of classic PKU children have significant influence on the curative effect of children.