Psoriasis is a disease that bothers the patient's life quality and appearance and the disease course requires long-term drug control. This case is a 70-year-old woman who was diagnosed as psoriasis at the age of 64. Although she was treated with steroid ointment, the effect was not obvious and satisfied. The diagnosis which was diagnosed by Traditional Chinese medicine clinic was blood and yin deficiency. The prescription was used to treat blood heats, nourish yin and moisturize dryness, with topical natural indigo cream. After several month treatments, her skin condition has been well improved.