Abstract： Objective:To evaluate trends in the use of proton beam radiation therapy (PBT) in patients with central nervous system (CNS) tumors in the United States and the factors associated with such use.Methods:The National Cancer Database was queried for CNS tumors patients between 2004 and 2021 to explore the time trend in the use of PBT by histology type, age at diagnosis, insurance, median household income level, education level, and hospital type. Multivariable logistic regression analysis was used to report the association of various factors with the use of PBT.Results:Of all the 192 696 CNS patients, 5 901 (3.1%) received PBT, among whom 4 109 (69.6%) were ≥18 years of age. The use of PBT in CNS tumors increased from only 1.0% in 2004 to 11.4% in 2021. In patients who received PBT, embryonal tumor was the most common pediatric tumor while astrocytoma was most common adult tumor. Multivariable logistic regression analysis revealed that patients with glioblastoma, ependymoma, medulloblastoma, germinoma were more likely to received PBT compared to astrocytoma. Age<18 years, no-comorbidity, private insurance, higher household income level and being diagnosed in recent years were also positively associated with the use of PBT.Conclusion:The patients with younger age, no-comorbidity, higher household income, private insurance, diagnosed in recent years and certain tumor histologists are more likely to receive PBT in the United States. The use of PBT increased from 1.0% in 2004 to 11.4% in 2021. However, there is still a distinguished gap between the number of patients who should receive PBT and the number of patients who received PBT.