The Equation of State of Quasi-Particle Model at Finite Chemical potential and Quark Star, H. S. Zong, Department of Physics, Nanjing University, China − In this paper, we employ the equation of state (EOS) of the quasi-particle model which incorporates the effect of vacuum negative pressure to study the properties of quark star.  In our model the EOS has the correct behavior required by QCD in the small and large μ limit.  We employ this EOS to calculate the mass-radii relation and mass-energy density relation of quark star.  Our results are found to be consistent with the most recent astronomical observations.