The influences of 3 phosphate fireretardants(monoammonium phosphate MAP, diammonium phosphate DAP and ammonium polyphosphate APP) on the curing process of UF resin adhesive were studied by differential scanning analysis (DSC). The results indicated that: 1) APP and MAP could be incorporated in a UF resin to formulate a fireretardant adhesive system; 2) APP and MAP played a dual role in the curing of UF, they could decrease the activation energy of curing reaction of UF and therefore lower the onset temperature, however the curing speed and the final cure degree of a fireretardant UF were less than that of a UF without APP or MAP; 3) DAP inhibited almost completely the curing of UF and thus was not a suitable agent for fireretardant UF adhesive systems.