Objectives: The two criteria to clarify the toxicity of a herbal diet are well known. Although mechanical analysis of effective ingredients, a western approach, is widely used, the toxicity presence classification through the herbal analysis from a viewpoint of a theory of the herbal medicine properties has been disregarded. This study is for the safe use of a herbal diet through classification and study of toxicity presence in the herbal diet from the view of a theory of herbal medicine properties, one of the methods of Oriental Medicine. Methods: We classified and studied the toxicity presence in four kinds of herbal diets, waters and grains, animals groups, fruits and vegetables, and herbs and trees, excluding mineral natural drugs, of 1,400 kinds of medicines in 16 chapters of Tang-aec-pyeon, Dong-ui-bo-gam, for which the herbal analysis from a viewpoint of the theory of the herbal medicine properties has been used. The criteria of the toxicity presence in the herbal diet have been largely classified into the toxicant and the non-toxicant, and the toxicant is in turn classified into the insignificant, the medium and the significant. The category to clarify herbal diet has been limited to simultaneous utilization of food and natural drugs. The main text is Dong-ui-bo-gam, although diverse other references have also been used. Results: There are toxicant diets: a kind of tortoise meat of animals groups; five kinds of grains part in fruits and vegetables: aengdo, peach, oyat, small apple and gingko nut; and 12 kinds of vegetables part in fruits and vegetables: ginger, oriental cabbage, lettuce, chongbaek, onion, garlic, leek, fern, houttuynia cordata (myeol), pyeongji, geundae, and spinach, which should be prohibited from long-term use both as food and medicine. Conclusion: If herbal diet is used as health food supplements or food, the toxicity presence should be considered on the grounds of an Oriental Medicine theory of the herbal medicine properties.