5-Amino-1,10-phenanthroline was prepared by the reduction of 5-nitro-1,10-phenanthroline with hydrazine hydrate in presence of Pd/C catalyst,and characterized by IR,UV,1 H NMR,MS and elemental analysis.The paper investigated the influences of temperature,time,and quantities of catalyst and hydrazine hydrate used on product yield.Under optimum conditions,parallel experimental results show that the yield of 5-amino-1,10-phenanthroline can reach 92.9%.The reduction method of hydrazine hydrate in presence of Pd/C catalyst is a kind of environment-friendly and simple reduction method.