Molecular biology testing has gradually become a routine diagnostic and therapeutic aid for malignant brain tumors! It is well known that the same pathological diagnosis, such as medulloblastoma, has a significantly different prognosis! Among the factors affecting or related to the prognosis, the molecular biology, i.e., the difference of genes, determines the different prognosis of patients! Therefore, conducting molecular biology tests plays a significant role in malignant medulloblastoma! Molecular typing of medulloblastoma tumors: mainly according to the different signaling pathways of the tumor, it is divided into: Shh type and Wnt type, in which Wnt type tends to have a better prognosis while Shh type generally has a better prognosis, and currently also found that there are also Group3 and Group4 groups, which shows that the molecular biological behavior of medulloblastoma tumors is still very complex, and the future MB tumor staging and prognosis will include certain molecular markers, which can be used to identify the molecular biology of medulloblastoma tumors. The search for key molecular markers in medulloblastoma will allow for more specific grading of medulloblastoma and determination of patient prognosis. Establishing a more accurate staging system will allow for better differentiation between high-risk and average-risk MB, and for finding the most effective therapeutic targets, and thus the best treatment strategies. Genetic variants of medulloblastoma: Currently, the main genetic findings are chromosomal variants, of which the 17q variant is more common, as well as deletions of 8p, 10q, and so on. Currently, we routinely perform molecular biology testing for medulloblastoma, and preliminary results show that every patient is found to be sensitive to a certain chemotherapy regimen! This finding also provides a good guidance for us to carry out postoperative radiotherapy adjuvant therapy for medulloblastoma!