To improve fire-resistance of high-pressure laminates （HPL） made from thermosetting resin impregnated papers, an organic compound of phosphorus was added to the phenol-formaldehyde resin. Depending on whether the phosphorus compound was added before or after the preparation of PF resin, it acted as a reacting flame retardant or an additive flame retardant respectively. Results found that superior fire resistance resulted when it acted as a reacting flame retardant. When used as an additive flame retardant, the fire-resistance of the HPL increased as the level of phosphorus compound increased. When the amount was beyond 7% （on the absolute dry weight of PF resin）, the HPL no longer supported combustion.