Abstract: There are two genes encoding H3F3A and H3F3B in human histone H3.3 variant. The mutation rate of G34R/V is lower than that of K27M in high-grade glioma. H3.3 G34 mutation presents a histopathologically heterogeneous, with microscopic characteristics of typical glioblastoma (GBM), central nervous system primitive neuroectodermal tumors (CNS-PNET), or even astroblastoma. Moreover, G34-mutant tumor has its unique manifestation in the age of onset, tumor location, and prognosis. CNS tumors with H3.3 G34 mutations displayed uniform epigenetic signatures, suggesting a single biological origin. Chromosome 3q and 4q deletions were more common and specific in G34-mutant tumors, which were often accompanied by PDGFRA or CCND2 amplification, than in other subtypes of GBM. Here, we review the clinicopathological and molecular genetic characteristics of histone H3.3 G34R/V mutant gliomas.