In this experiment we used the process of iodimetric titration which is one branch of redox titration. The sample in this experiment is two fruit juice brand and the analyte is ascorbic acid or vitamin C. First of all, we make iodine solution (that obtain from KI and KlO3 mix together) to be more standardization by using ascorbic acid. Before titration we put 5 drop of 1% starch into ascorbic acid and two fruit juice sample because 1% of starch is an indicator. In part of standardization, we titrate solution until ascorbic acid change to blackblue color. Including, part of determination of vitamin C in fruit juice, we titrate the sample until it change color.