Chocolate is a unique food and one of the important sources of biologically active substances which have shown a special antioxidant effect in the human body. In recent years, with the advent of functional foods, researchers are seeking to strengthen micronutrient products to increase their health effects. The proposed research is for the enrichment of chocolate, oleaster powder in levels of 5, 10, 15 and 20% instead of sugar. The researchers proved that oleaster is rich of polyphenols, flavonoids, vitamins, tannins and especially fibers. And used in traditional medicine as an anti-nausea drug due to its high tannin content. In this study, to increase the antioxidant and sensory properties, Mentha extract with constant dose added to all treatments and functional chocolate was produced. The results of the experiments indicated that polyphenols, flavonoids, anthocyanins increased, as well as an increase in the free radical DPPH concentration in the presence of oleaster powder. In this research, due to the positive effect of tannin in eliminating nausea, the tannins and the kinetics of its decomposition (constant K) and the half-life of tannin T_1/2 in chocolate were measured that the results indicate that this composition is stable in mint chocolate. Due to the undesirable gass taste caused by high tannin, the mint extract had a positive effect on improving the sensory properties and the mind of the audience was primarily concerned with the mild extract coldness. According to the results, this product can use as a nutritional and nutritional health enhancer.