  We will report centrality dependence of chemical freeze-out temperature
($T_{ch}$), light quark chemical potential ($\mu_{q}$), strange quark chemical
potential ($\mu_{s}$), and strangeness saturation factor ($\gamma_{s}$) in
Au+Au collisions at $\sqrt{s_{NN}}$ = 130 and 200 GeV. A systematic study for
combination of ratios for chemical freeze-out fit is studied and we have found
small ombination dependences. The results show $\gamma_{s}$ increasing with
centrality but the other parameters have less sensitivity to the centralities.
