Baby spilt milk and spit up in the cause, performance and nature are very different, spilt milk is mostly belong to the digestive system structure and function related to the normal situation, spit up is mostly associated with digestive function abnormality. The difference between baby milk spillage and spitting up, first of all, from the cause of occurrence, milk spillage is mostly associated with feeding posture or overfeeding plus the normal digestive physiological structure and function of infants and young children are not yet fully developed and other circumstances; while spitting up with the digestive tract obstruction and other abnormalities have a certain relationship. Moreover, the way of performance of the two are also different, overflow of milk performance is mild more than only a small amount of milk out, while the intensity and amount of spit up is greater than the former can be jet-like. Spilt milk is usually made up of fresh milk from feedings, whereas spit-up may have a sour odor and yellowish-green bile-like vomit. It is recommended that prolonged overflow of milk or sudden spitting up and other abnormalities are not relieved after appropriate adjustments should be timely medical care, improve the abdominal ultrasound and other relevant auxiliary examination to determine the cause of the disease and then targeted treatment.