The solubility of D-xylose in formic acid and binary solvents of formic acid with formic acid and acetic acid, propionic acid, n-butyric acid or isobutyric acid was measured in the temperature range from 300.35 to 325.05 K using the synthetic method by a laser monitoring technique at atmospheric pressure. The solid-liquid equilibrium data will provide essential support for industrial design and further theoretical study. The experimental data show that the solubility of D-xylose in formic acid and in the mixtures of formic acid + acetic acid (1 : 1), formic acid + propionic acid (1 : 1), formic acid + n- butyric acid (1 : 1), and formic acid + isobutyric acid (1 : 1) increases with temperature. The Apelblat equation, the model, and the ideal solution equation correlate the solubility data well.