Objective In contrast to conventional radiotherapy ,analyze the dosimetry and prognosis of 3D conformal radiothera-py in the treatment of gliomas with different pathological stages .Methods 97 patients with gliomas were selected ,and divided into two groups as conventional radiotherapy group (CR group) and 3D conformal radiotherapy group(3D group) .analyzed the influence of different radiotherapy to the gliomas in the same pathological stage .Compared the dosimetry differences between these two radio-therapies .Results There was no obvious differences in 3 year survival rate between CR group and 3D group at low grade gliomas . But 3D group had better 3 year survival rate than CR group at high grade gliomas .And 3D group had lower rate of relevant sequel after radiotherapy .3D group had higher conformal index (CI) and average dosage of radiation than CR group .Conclusion 3D radio-therapy has better dosimetry and conformal index than conventional radiotherapy ,especially has better prognosis in high grade glio-mas and lower rate of relevant sequel after radiotherapy .