The aim of the work is to investigate the one-pot hydrolysis-oxidation of different lignocellulose feedstocks: hemicelluloses xylan and arabinogalactan as well as lignocellulose biomass (sulfate pulp, waste paper, silver grass and aspen wood). The target product of the process is formic acid. It is a valuable product which seems to be very perspective reducing agent or hydrogen source. The experiments have been carried out in the solutions of bifunctional Mo-V-P heteropoly acid catalyst which has the composition Co_0.6H_3.8PMo₁₀V₂O₄₀. The yield of formic acid equal to 40-43 mol% has been reached from hemicelluloses at 90-120 °C. 53, 45, 29 and 24 m/m% formic acid yields have been reached from aspen wood, silver grass, sulfate cellulose and waste paper, respectively.