The probability of jaundice 15mg/dl into the brain should be judged according to the gestational age of the baby and the level of bilirubin in the body, due to the existence of large differences in the individual, the size of the probability of jaundice 15mg/dl into the brain is also different, and should be analyzed according to the different situations. For babies of small gestational age or premature babies, if there are many complications after birth, jaundice 15mg/dl into the brain will occur when the body’s bilirubin level is low, for full-term babies, generally the higher the level of jaundice, more than 510 μmol/L, the higher the chance of entering the brain, and if the level of jaundice is within 342 μmol/L, the chances of entering the brain will be correspondingly reduced. Therefore, the chance of jaundice 15mg/dl entering the brain varies greatly according to different babies, some babies already enter the brain when their bilirubin level is low, and some babies will not enter the brain even though their bilirubin level is very high. When babies’ skin is yellowish, it is recommended to go to the hospital to check for jaundice and enter the brain and to treat it positively.