Abstract: In this paper a new catalytic-spectrophotomelric method is proposed for the determination of trace amounts of manganese(Ⅱ) in food. The method is based on the manganese-catalysed oxidation of xylene cyanole FFby potassium periodate with the use of 1,10-phenanthroline as an activator. If the sample solution is warmed in a thermostat at 60℃ and pHranging from 3.8 to 4.2, the method is of the best determinable sansilivity. The working curve is linear in the range 1.85~11ng·ml^-1 of manganese.