The specific heat of nickel-copper alloys containing 0 .0, 4.6, 9.3, 14.0 and 18.8 at .% Cu has been studied near the Curie temperature. The effective critical exponents of specific heat were analyzed using a simple power law; our results show that the value of the effective critical exponents depends on the concentration of impurities. Higher-order correction techniques are definitely necessary for analyzing the universality and symmetry of the exact critical exponents of specific heat.