This research evaluated how the composition of Yak-sun(oriental diet therapy), taken as a nutritional supplement with daily meals, can effect the medical condition of those suffering from modern diseases like obesity and hyperlipideia. We produced Yak-sun tea, determined its nutrient composition and physical characteristics and evaluated how this tea effects affects the active oxygen concentration inside the body by clinical practices. The study results indicated that this tea significantly decrease active oxygen concentration. We think that scientific and objective evaluation was done on the components of Yak-sun tea prescription. We concluded that we could apply the components not only in the form of tea, but also in other food forms. The information we received from this conclusion will provide basic information for the application of oriental medicinal resources into other foods and will also be a steppingstone in the field of functional food research for the development of medicinal herbs which is already an important research field world-wide.