Background and Objectives : There are four kinds of formulas for invigorating the kidney to cure its asthenic syndrome based on the types of preparation formulas : Boshintang, Boshinhwan, Boshinsan, and Boshingaeng. There are 16 kinds of Boshintang, 28 kinds of Boshinhwan, 3 kinds of Boshinsan, and one kind of Boshingaeng. Combination of herbal medicines, carried out in formulas for invigorating the kidney, consists of various kinds depending on medical scientists' personal experience in medical treatment without any general principles, which makes it difficult to apply it to clinical use. The objectives of this study lie in theoretical establishment of Boshintang for curing the asthenic syndrome of kidney through analyzing the component medicines and combination principles of Hyeongok's Boshintang, and furthermore, maximizing the clinical use of Boshintang. Methods : This study analyzed the component medicines and combination principles of Hyeongok's Boshintang based on the theory for properties and tastes of herbal medicines from the ${\ulcorner}$Yellow Emperor's Canon of Internal Medicine${\lrcorner}$ , the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine, and the five elements doctrine. Hyeongok's Boshintang is an even prescription, composed of 6 kinds of ingredients : No.1 Fructus Lycii (3don;11.25g), No.2 Radix Polygoni Multiflori (1don:3.75g), No.3 Sarcucarpium Corni (1don), No.4 Fructus Schisandrae (1don), No.5 Rhizoma Anemarrhenae (5poon: 1.875g), and No.6 Cortex Phellodendri (5poon) Results : There are three methods for curing the asthenic syndrome of kidney according to the five elements doctrine : invigorating the kidney, invigorating the lung and purging the spleen. First, if you suffer from the asthenic syndrome of the kidney, you need to invigorate your kidney. There are two available methods, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each imply the bitter taste and the cold property invigorate the kidney. In the case of taste invigoration, two herbal medicines with bitter taste, Fructus Lycii and Radix Polygoni Multiflori, are combined into the principal and assistant herbal medicine, respectively. For property invigoration, two herbal medicines with the cold property, Rhizoma Anemarrhenae and Cortex Phellodendri, are combined into adjuvant herbal medicines. Secondly, if you suffer from the asthenic syndrome of the kidney, you need to invigorate your lung which is mother in the mother-child relationship in inter-promotion among the five elements. There are two methods to invigorate the lung, including taste and property invigoration according to the theory for properties and tastes of herbal medicines. They each mean the sour taste and the cool property invigorate the lung. Therefore, it is important to use sour herbal medicines for taste invigoration and cool ones for property invigoration. Both bitter and cool herbal medicines, Rhizoma Anemarrhenae and Cortex Phellodendri, are combined into adjuvant herbal medicines. Lastly, if you suffer from the asthenic syndrome of the kidney, you need to purge your spleen which is an element being surpassed in the relationship between the elements surpassed and ones not surpassed in inter-restraint among the five elements. There are two methods to purge the spleen, which include taste and property purgation according to the theory for properties and tastes of herbal medicines. Taste purgation means to purge the spleen with bitter taste and property purgation to purge the spleen with cool property. Therefore, it is important to use bitter herbal medicines for taste purgation and cool ones for property purgation. Both bitter and cool herbal medicines, Rhizome Anemarrhenae and Cortex Phellodendri. were combined to purge the spleen and invigorate the kidney. In addition, Rhizome Anemarrhenae and Cortex Phellodendri are combined as dispatcher herbal medicine, reinforcing the kidney energy. Conclusions : First, to cure the asthenic syndrome of the kidney, the methods of invigorating the kidney and the lung, and purging the spleen should be used according to the five elements doctrine. Secondly, herbal medicines appropriate for those treatment methods should be chosen according to the theory for properties and tastes of herbal medicine and thirdly, the combination of those herbal medicines should be carried out according to the theory for principal herbal medicine, assistant herbal medicine, adjuvant herbal medicine, dispatcher herbal medicine. As a good example, Hyeongok's Boshintang is combined according to the above theories. In conclusion, this formula was created by applying to the theory for properties and tastes of herbal medicines.