Higgs boson decay into bottom quarks and uncertainties of perturbative QCD predictions

Different methods for treating the results of higher-order perturbative QCD calculations of the decay width of the Standard Model Higgs boson into bottom quarks are discusssed. Special attention is paid to the analysis of the $M_H$ dependence of the decay width \Gamma(H\to \bar{b}b}) in the cases when the mass of b-quark is defined as the running parameter in the $\overline{MS}$-scheme and as the quark pole mass. The relation between running and pole masses is taken into account in the order ${\alpha }_s^4$-approximation. Some special features of applications of Analytical Perturbation Theory (APT) are commented.