Yin deficiency in children can be characterized by the following clinical symptoms: firstly, Yin deficiency in children can cause dry mouth and lips and dry skin, and very little urine, often with a red tongue and little tongue coating. The next symptom is internal heat, because Yin deficiency causes heat hyperactivity, which leads to an increase in heat symptoms. For example, children may have a sore throat and dry eyes, very yellow urine, and very dry stools. For children with Yin deficiency and internal heat, on the one hand, they should be treated with Yin tonification, and on the other hand, they need to promptly reduce heat treatment, which can be done by applying Zhi Bai Di Huang Wan, which can have a good effect of nourishing Yin and reducing heat.