Abstract: In December 2016,Muddy Waters issued a short report on Huishan Dairy,pointing out that the company had whitewashed statements and exaggerated financial leverage. In the months that followed,Huishan's share price plunged. The failure of internal control is the source of this Muddy Water short selling event. As the first barrier to ensure the normal production and operation of enterprises,it did not play its due role. In order to study the role of internal control in enterprise operation,the internal control situation of Huishan Dairy was analyzed through the framework of five elements of internal control. It is found that the enterprise has five problems: weak control environment,imperfect risk assessment mechanism,ineffective control activities, poor information communication and insufficient supervision. In view of these problems, corresponding optimization suggestions are put forward,hoping to provide some references and suggestions for the industry to optimize internal control.

Key words: internal control, supervision, Huishan Dairy