XAFS technique has been used to quantitatively determine the local structure evo lutions of ultrafine Ni-P and Ni-Ce-P amorphous alloys prepared by chemical redu ction during the annealing process.Using an asymmetric atom distribution functio n model of convolution of a Gaussian function PG and an exponential f unction PE for XAFS data analysis,we obtained that the average bond l ength Ｒj,coordination N,thermal disorder factor σT,and s tatic disorder factor σS for the Ni-Ni first neighbor shell are 0.27 1nm,10.0,0.0060nm and 0.028nm in the Ni-P and 0.271nm,10.6,0.0070nm and 0.030nm in the Ni-Ce-P initial samples,respectively.It indicates that the σS is rather large and about three times larger than that of σT.The Ni -P sample crystallized under the annealing temperature of 573K,while the crystal lizing temperature of Ni-Ce-P sample is about 100K higher.The result suggests th at the thermal stability of Ni-Ce-P sample is significantly increased by the add ition of 2% Ce element.After being annealed at 773K,both Ni-P and Ni-Ce-P sample s are fully crystallized as metallic Ni and an amount of crystalline Ni3P.Furthermore,we have found that the static disorder σs of Ni-Ni coordination shell is 0.011nm for the Ni-P and still larger for the Ni-Ce-P samp les annealed at 773K,despite their radial distribution functions around Ni atoms are similar to that of Ni foil.It implies that the Ni lattice obtained from the crystallized Ni-P and Ni-Ce-P amorphous alloys is significantly distorted by th e interaction of P element.