Abstract: The influences of different current quark masses on the properties of hybrid stars were studied via the relativistic mean field theory and the effective mass bag model. The numerical analysis shows that with the increase of the current quark mass the phase transition density increases, the equation of state for the mixed phase region stiffens, the maximum mass and the corresponding radius increase. The maximum mass of the star increases from 1.4 M⊙ to 1.63M⊙ （M ⊙=1.99×1030 kg is the mass of the sun）, and the corresponding radius of the star ranges from 10.24 km to 11.64 km with the increase of the current mass of the strange quark from 90 MeV to 200 MeV.

Key words: current quark mass, hybrid star, equation of state, mass-radius relations