Sheet-like nanocrystalline Cu3P and spherical nanocrystalline Ni2P with hexagonal phases were successfully obtained under mild solvothermal conditions based on the reactions of CuCl2. 2H(2)O, NiCl2. 6H(2)O with elemental phosphorus in ammonia liquor systems. The phase, grain size, morphology and purity were determined by XRD, TEM and XPS, respectively. The ammonia system and active yellow phosphorus played important roles in the formation of nanocrystalline Cu3P and Ni2P. A possible mechanism is proposed.