Exchange of attribute credentials is an important means to establish mutual trust between strangers who wish to share resources or conduct business transactions. Automated trust negotiation (ATN) is an approach to regulate the exchange of sensitive credentials by using access control policies, so as to protect sensitive credentials, policies and private privacy, and to improve negotiation efficiency and successful negotiation establishment rate. A detailed review of the research on ATN is presented based on the survey and classification of the current negotiation techniques. According to the precise investigation on ATN, the pitfalls of ATN are pointed out and the reasonable rules that ATN should observe are put forward, meanwhile, the development trend for ATN is proposed.