Abstract: A new spectrophotometric method for determination of Ni(Ⅱ) was developed based on the color reaction between 2-aceto-pyridine condensation(2’-pyridine imido-group) hydrazine(2-AP-(2’-PI) H) and Ni(Ⅱ).In a medium of pH 7.5,2-AP-(2’-PI) H reacts with nickel to form a yellow complex with a molar ratio of 1:1.In the range of 350~480 nm wave length,this complex has bigger absorptivity,the apparent molar absorptivity is 1.45×104 L·mol-1·cm-1 at 420 nm.Beer’s law is obeyed for Ni2+ in the range of 0.10..