γ-Aminobutyric acid (GABA) is basically neurotrasmitter produced by the decarboxylation of L-glutamic acid catalyzed by glutamic acid decarboxylase (GAD), which was known to convert monosodium glutamate (MSG) to GABA. To investigate enhancement of reversion rate of GABA, the yogurt fermentation with addition of nanoparticle winter mushroom and hydroponic ginseng was used. The conversion rate was revealed to nanoparticle winter mushroom and hydroponic ginseng fermenter (88%) > winter mushroom fermenter (52%) > nanoparticle winter mushroom fermenter (44%). The results showed that nanoparticle winter mushroom and hydroponic ginseng supplemented substrates for enhancement of GABA may be used more effectively as one of potential sources of functional foods.