Curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5- dione) is a natural biological active substance with an antioxidant activity. The ability of curcumin to inhibit the free radical mechanisms can be used in a prevention of diseases such as cancer and coronary heart disease. The UV-VIS spectrophotometric and chemiluminescent dynamic methods for determination of antioxidant activity of curcumin were developed. The spectrophotometric method includes investigation of the interaction between DNA, isolated from HL-60 cells, and curcumin. The decreasing of the absorption of curcumin in the presence of HL-60 DNA against the blank sample can be a measurement for some complex formation between curcumin and DNA. The chemiluminescent method involves three tests for detection of luminol - depending chemiluminescence on the base of model systems which generate superoxide, hydroxide and hypochlorite radicals. The strongest decay of chemilunimescence was registered at the highest concentration of curcumin (100 μmol/L).