  We examine whether the parameters in the Higgs sector of the minimal
supersymmetric standard model can be determined by detailed study of production
cross section and decay branching ratios of the Higgs particle. Assuming that
the lightest CP-even Higgs boson ($h$) is observed at a future $e^+ e^-$ linear
collider with $\sqrt{s}=300\sim500$GeV, we show that the value of CP-odd scalar
mass is determined from the ratio of the two branching ratios, $Br(h\to
b\bar{b})$ and $Br(h\to c\bar{c})+Br(h\to gg)$, almost independently of the
stop mass scale.
