Abstract: A simple and rapid screening test to determine the real amount of vitamin C contained in fruit juices daily products was established by Prussian blue. The ferric chloride was reduced by vitamin C and then reacted with potassium ferricyanide to form a blue solution of Prussian blue. The developed color was monitored at absorption wavelength of 709 nm. Optimum conditions of substrate concentrations were investigated. Interference effects of various substances including glucose, fructose and sucrose have been studied. The vitamin C kit was fabricated under the optimum conditions. The kit contains all necessary reagents and operates on a very simple protocol. The detection level of this semi-quantitative kit has been set at 0.01 mM of vitamin C with acceptable of precision and accuracy. It has been successfully applied to analyze the vitamin C in fruit juices and the results were compared well to a titration method. These results demonstrate that the screening test was suitable for the quality control of vitamin C with simple, rapid, precise and accurate and convenient approaches for analysis of fruit juices.