In this study, kinetics of formic acid-catalyzed xylose dehydration into furfural and furfural decomposition was investigated using batch experiments within a temperature range of 130-200 degrees C. Initial xylose and furfural concentrations up to 0.2 and 0.08 mol/L, respectively, were used. The room temperature pH of the formic acid catalyst solution was between 0.9 and 1.7. The kinetic model used was based on a specific acid catalysis model and included the prevailing hydrogen ion concentration in reaction conditions. The study showed that the modeling must account for other reactions for xylose besides dehydration into furfural. Moreover, the reactions between xylose intermediate and furfural play only a minor role. The study also showed that kinetic modeling of xylose and furfural decomposition reactions must take the uncatalyzed reaction in water solvent into account.