Disclosed are a pharmaceutical composition and a health functional food for the prevention and treatment of diabetic peripheral neuropathy, comprising an herb extract of a mixture of 3.5:1 Dioscorea Rhizoma:Dioscorea nipponica (w/w). Having the ability to synergistically increase in vivo levels of nerve growth factor, compared to the extracts from the herbs alone or her mixtures of other weight ratios, the mixed herb extract is effective for preventing the apoptosis of nerve cells and promoting nerve regeneration. Thus, it can be applied to pharmaceutical compositions and health function foods preventive and curative of diabetic peripheral neuropathy.