Abstract: Glioblastoma(GBM)is one of the most common primary intracranial tumor that has high degree of malignancy,invasive ability and a fatal prognosis.In recent years,with the development of modern technology in biomedical sciences,the understanding on GBM has developed gradually from pathological diagnosis to molecular classifications,which is based on the molecular characteristics of genetic signatures.Based on gene expression and DNA methylation patterns,primary glioblastoma is divided into four subtypes,including the classical,neural,proneural and mesenchymal.These molecular classifications are closely relevant to the biological characteristics of glioblastoma.This review briefly introduces the molecular classifications of primary glioblastoma,but mainly focuses on the changes of the major genetic EGFR,PTEN and PI3K,CDKN2A in the classical subtype of GBM,and discusses the treatment strategies for primary glioblastoma.