Abstract: The virial theorem can be used to analyze the kinetic and potential energy of N-body gravitating system，which is widely used in astrophysics. Globular clusters have reached dynamical equilibrium through long-term two-body relaxation. We estimate the dynamical masses of four globular clusters NGC 1851，NGC 1904， NGC 7099 and NGC 5964 based on high-precision radial velocities and the virial theorem. The dynamical masses of the four clusters are 0. 99×10 ⁵ M⊙ ，0 . 54×10 ⁵ M⊙ ，0. 44×10 ⁵M⊙ and 4. 88×10 ⁵ M⊙ ，respectively.

Key words: virial theorem, globular cluster, radial velocity