Generally speaking, a six-month-old child can sit alone for a while. If the child does not know how to sit at this time, you can observe the child for a while and consciously cultivate this awareness. If the child still does not know how to sit in the following period, then you need to be vigilant and find out the cause of the problem and treat it in a timely manner. Generally speaking, the child can sit with the buttocks up at four months, can sit alone for a while at six months, and can sit alone for a long time after seven months. If the child is unable to sit at this time, it may be due to lack of training, lack of awareness, or abnormal development of the child’s nervous system, spinal development, or calcium deficiency. At present, this situation can be temporarily observed, parents for the child to carry out the appropriate awareness, cultivation and sitting training, if the follow-up is still unable to sit independently, it is necessary to go to the hospital in a timely manner, to identify the causes of symptomatic treatment.