The internationalization of education and practice has progressed rapidly in the field of engineering. Accrediting organizations are seeking to establish codes of ethics that will not only find favor with the many communities involved in the fields of engineering but also help the disciplines achieve their various professional and educational goals. In order to actively sanction the use of biotechnology, mobilize political support and opposition, and promote activities of relevant social movements, this paper attempts to discuss the importance of trust in the relationship between engineers and the public. It also examines the roles and responsibilities of engineers and behavioral scientists within the broader context of societal impacts of biotechnology. The study first reviews the history of code of ethics and the process of how the code becomes the source of trust between the profession and the public. Next, using the 2008 China earthquake as an example, the study discusses the ethical dilemmas between the profession and public. Finally, future challenges in the investigation of the societal impacts of biotechnology are presented.