Abstract: To explore the compatibility characteristics of herbs used for nourishing yin in formulas of kidney-yang tonification. It is noticed that the appearance frequency of such herbs for yin nourishment as Radix Rehmanniae Praeparata， Rhizoma Dioscoreae， Fructus Corni and Fructus Lycii comes out on the top. Either the dosage ratio or the number of herbs of yin nourishment in the modern formulas for tonifying kidney yang is evidently increased than that of the ancient formulas， with the application scope being expanded. Hence， it is believed that compatibility of herbs for nourishing yin in formulas of kidney-yang tonification has become a major compatibility form in the clinical practice. When deficiency of kidney essence is obvious， the dosage of herbs for nourishing yin should be increased. While when the internal generation of deficient cold takes a dominant place， the dosage should be decreased， which is able to provide a reference for the reasonable application of formulas for kidney-yang tonification in clinical practice.