30 days baby jaundice persists not to go down, the reason is as follows: first, breast milk jaundice, baby spirit, appetite state is good, big, urine is normal, jaundice persists not to go down when consider breast milk jaundice possibility is bigger, suggest temporarily stop feeding breast milk for 3-5 days, give the child to eat gardenia berry, mamma love, promote liver and intestinal circulation, promote jaundice to go down. Generally speaking 3-5 days later jaundice value will be reduced by half, then consider breast milk jaundice. Second, the child’s co-infection, 30-day-old baby with viral infection, bacterial infection will lead to jaundice persists, need to target the cause of anti-infection treatment, the symptoms will be relieved. Third, congenital hypothyroidism, typically characterized by constipation, persistent jaundice, low body temperature, low basal metabolic rate, it is recommended to go to the hospital in time to check the thyroid function, combined with the clinical manifestations of further diagnosis and treatment.