Six-month-old babies can not sit may be a normal phenomenon, may also be the brain motor function development delay or lack of vitamin D and calcium and so on. If the baby’s other motor development reaches the level of babies of the same age, just can’t sit yet, it can be considered as a normal phenomenon, because there are individual differences in the growth and development of babies, in addition to the weight gain is relatively fast or less training of the sitting posture will lead to the baby can’t sit yet in June. If the 6-month-old baby not only can not sit, and can not complete the same age of the baby can complete other movements (such as rolling the body, etc.), then it may be due to delayed development of brain motor function. In addition, vitamin D and calcium deficiencies can also affect the development of the spine, which in turn can lead to the baby’s inability to sit up. Generally, 6-month-old babies can sit up with the help of external force, 7-month-old babies can sit alone for a few moments, and 8-month-old babies can already sit very steadily. If your 6-month-old baby can’t sit normally, you can increase your baby’s sitting training or related treatment after consulting your doctor.