Babies often spit up bubbles may be normal phenomenon, milk residue, respiratory tract infection and other related. 1. Normal phenomenon: the baby’s oral cavity capacity is relatively small, but saliva secretion, saliva is not swallowed in a timely manner, there may be the phenomenon of spitting bubbles, this situation is normal. Part of the baby feel saliva fun, this time spit bubble is also a normal performance. 2. Milk residue: the baby will have milk residue in the mouth after drinking milk, saliva secretion will bring out the milk, the phenomenon of spitting bubbles, you can clean up the mouth in time. 3. Respiratory tract infection: If the baby has pneumonia, the symptoms may not be obvious in the early stage, and can show symptoms such as spitting bubbles and choking. The baby often spit up bubbles may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor’s treatment.