If medulloblastoma grade IV is resected cleanly, the recurrence time will be relatively long, and usually it may recur in 2~3 years after operation, and if the surgery can not remove it completely, usually it may recur within half a year after operation. 1. Medulloblastoma grade IV is very serious, patients will show cerebellar ataxia, gait instability and increased intracranial pressure, do CT can show solid high density in the posterior fossa of the skull, and obvious enhancement of the occupying lesion, often due to the soft meninges and the ventricular wall has a spread, easy to appear abnormal signal. The tumor is largely gray-red in color and soft, and some tumors resemble sticky snot, which can be aspirated by suction during surgery. Some tumors are like sticky snot, which can be aspirated by suction during surgery. Some tumors are a little hard or can be seen as a large bleeding mass. 2. After surgical resection, patients need to receive adjuvant radiotherapy, chemotherapy and other comprehensive treatments in order to prolong the survival period of patients as much as possible. Therefore, when a child develops medulloblastoma, he/she should go to regular pediatrics and oncology hospitals for formal evaluation and selection of individualized treatment plan, in order to achieve the best therapeutic effect. After treatment, we should pay attention to the evaluation of the child’s outcome and change the treatment plan in time.