Nitric oxide (NO) is a kind of free radical, also is a signaling molecule, which universally distributed in the tissues of organism. NO play important role in the dermato-, cardia-, encephalo-, hepat- and immunological regulation on the physio- and patho- situation. Recently studying show that NO can bifunctionally regulate the apoptosis of keratinocytes, which play an important role in the occurrence and development of many skin diseases. However, the regulatory mechanism still can't be completely elucidated at present time. In this review, we are reviewing the recent investigation progress on the apoptosis of keratinocytes and some diseases of skin that related to the regulating disturbance of NO.