A chemiluminescent method with gold nanoparticles for determination of vitamin C has been presented. Gold nanoparticles highly increased chemiluminescence intensity of lumimol-H2O2 system by its catalytic effect. The gold nanoparticles enhanced chemiluminescent method is applicable for the determination of an antioxidant such as vitamin C. When vitamin C was introduced to the lumimol system with gold nanoparticles, chemiluminescence intensity was reduced with the concentration of the added vitamin C. Low concentrated vitamin C solutions in the range of 1×10^(-3)-1×10^(-9) M were produced reduced chemiluminescence intensity of lumimol-H2O2 with gold nanoparticles system.