Persimmon is an important fruit plant that has been grown for a long time in Vietnam. However, if persimmon fruit is ripen naturally, it will have acrid taste and is not edible. The purpose of this study was to reduce the tannin present in persimmon fruit by ripening process using exogenous ethylene gas at different concentrations and times. Then the variation of some quality indicators of persimmon fruits are investigated during storage. Results showed that, persimmon fruit treated with ethylene at 80 ppm for 12-24 hours obtained the best effect, tannin content decreased significantly. In addition, the quality of the persimmon fruit varies in the desired direction.