Asteroseismology is a powerful tool for probing stellar interiors and determining stellar fundamental parameters. In the present work, we adopt theme chi(2)-minimization method but only use the observed high-precision seismic observations (i.e., oscillation frequencies) to constrain theoretical models for analyzing solar-like oscillator KIC 6225718. Finally, we find the acoustic radius To is the only global parameter that can be accurately measured by theme chi(2)-matching method between observed frequencies and theoretical model calculations for a pure p-mode oscillation star. We obtain tau(o) = 4601.5(-8.3)(+4.4) seconds for KIC 6225718. It leads that the mass and radius of the CMMs are degenerate with each other. In addition, we find that the distribution range of acoustic radius is slightly enlarged by some extreme cases, which posses both a larger mass and a higher (or lower) metal abundance, at the lower acoustic radius end.