To address the problem of formaldehyde-free flame retardation of wood particleboard, a novel phosphorus-containing compound, di(2,2-dimethyl-1,3-propanediol phosphate) urea (DDPPU) was synthesized. DDPPU was used as flame retardant for wood particleboard. The flammability of treated wood particleboard systems consisted of wood particles, polyurethane (PU) adhesive, and different flame retardant formulations were investigated by limiting oxygen index (LOI). The results of LOI indicate that DDPPU could improve the flame retardancy of wood particleboard. However, when H3BO3 was used as the second flame retardant component and combined with DDPPU, the flame retardant wood particleboard could obtain the highest LOI analysis shows that treated wood particleboard can decrease the initial decomposition temperature, and that at higher temperatures the degradation rate are lower than the untreated wood particleboard. Furthermore, wood particleboard treated with DDPPU/H3BO3 has a higher yield of residue char at 600 degrees C than that treated with other flame retardant systems. The ability of char formation of these samples agrees with the order of LOI values. (C) 2008 Wiley Periodicals, Inc.