  We take the Dyson-Schwinger equation (DSE) approach of QCD to study the phase
transition and the equation of state of cold dense matter. Besides the bare
vertex and Gauss gluon model, we take into account an improved truncation
scheme, the CLRQ vertex and infrared-constant gluon model. For the dynamical
chiral symmetry breaking solution of the DSE, we require that the emergence of
quark number density to be at the chemical potential for the nuclear liquid-gas
phase transition to take place, by incorporating a chemical potential dependent
modification factor to the gluon model. The result shows that our modified
scheme can not only describe the phase transition of the cold dense matter well
but also the deduced equation of state of the matter can describe the recent
astronomical observations consistently.
