The study for generating and scavenging peroxynitrite anions (ONOO,−,) is an urgent task in free radical biology and medicine. Therefore, a novel chemiluminescence system for producing and measuring ONOO,−, has been established. The optimal conditions for detecting ONOO,−, were evaluated. The method can be described as follows. A mixture solution containing 10mmol/L hydroxylamine, 0.5mol/L NaOH and 1mmol/L EDTA was stirred vigorously in aerobic conditions for about 3h to form ONOO,−,. Certain amount of MnO,2, powder was added to the mixture solution to eliminate H,2,O,2, generated in the reaction. Then 100μL antioxidant and 860μL 0.1mol/L carbonate buffer (pH10) were added into a test tube. By adding 40μL filtrated ONOO,−, solution into the tube, chemiluminescence (CL) reaction was initiated. Ten seconds after the solution was uniformly mixed, CL intensity of the reaction solution could be determined in a measurement of 10 seconds. The method was tested with tea polyphenol, ascorbic acid, rutin and baicalin, whish are known to have effects of scavenging ONOO,−,. The tests show that the system is sensitive, low−cost, credible and easy method for screening ONOO,−,.