Nano melamine phosphate(NMP) flame retardant was synthesized using melamine and phosphoric acid as reagents by means of a solvothermal method. The prepared NMP was then characterized by means of Fourier transform infra-red spectroscopy, X-ray diffraction, and transmission electron microscopy. Effect of solvents, different kinds of surfactants(i.e. SDS, CTAB and NP), reaction temperature and time on the morphology of reaction product was investigated. It is found that the NMP can only be obtained by using benzene as a solvent. If distilled water and anhydrous ethanol were used as solvent, the particle size of the product is in micro scale. As reaction temperature or reaction time increases, the morphology of the products changes greatly. Moreover, types of surfactants have a great influence on the morphology of the products. Moreover, The polyethylene glycol toughened phenolic foam with addition of NMP exhibits a flexural strength 39% higher than that with addition of micro MP.