The prescription of Zhi Gan Cao Tang (? Decoction of prepared Licorice) is made for the syndrome of both yin and yang deficiency of the Heart, with the effects of tonifying yin and nourishing blood, activating yang and restoring normal pulse, and evenly tonifying yin and yang. However, in clinical practice, the symptoms may vary greatly. The heart rate may be slow or fast; and the symptoms may belong to the cold or heat, excess or deficiency syndrome. Therefore, the treatment should be based on syndrome-differentiation. We can learn from the above sample cases. The two patients with bradycardia needed to carry pacemaker. Their TCM differentiations were different, one due to insufficiency of yang-qi should be treated based on the principle of restoring yang from collapse; while the other due to obstruction of collaterals by phlegm and blood stasis should be treated based on the principle of resolving phlegm, promoting circulation of blood and dredging the collaterals. However, they used the same prescription of Zhi Gan Cao Tang (? Decoction of prepared Licorice) with different modifications, and both of them got quite good therapeutic effects. We can also learn from the other three cases of tachycardia. Based on western medical analyses, the 3 patients had different etiology, clinical manifestations, and ECG findings. However, they were treated with the same prescription of Zhi Gan Cao Tang (? Decoction of prepared Licorice), with modifications made according to the different accompanying symptoms. As a result, all of the three patients got marked therapeutic effects.