The thermal degradation of wood treated with basic nitrogen compounds and phosphoric acid was studied in air and nitrogen by differential thermal analysis and thermogravimetry from ambient temperature to 650degreesC. From the resulting data, kinetic parameters for different stages of thermal degradation were obtained following the method of Broido. For wood and flame-retardant wood, the values of E-a for decomposition Were found to decrease from 126 to 74 kJ . mol(-1). The values of char yield were found to increase from 5.4 to 31.5%, and the limiting-oxygen index increased from 18.5 to 40, which indicated that the flame retardancy of wood treated with chemicals was improved. A flame-retardant mechanism for the thermal degradation of samples was proposed.