Persuasion is one of the most effective tools to help change others' attitudes or behaviors (Dillard & Pfau, 2002). Using available present-day technology to assist persuasion is almost as effective as persuasion itself (Fogg, 1999). The first major breakthrough in this relationship was the technology that allowed easier production and distribution of books, flyers, pamphlets, billboards and other forms of written and visual communication. With the introduction and advances of computers and other new technologies, persuasion based on technology is getting smarter. As a result, technology-centered persuasion is rapidly developing. Dr. B.J. Fogg (1999) of Stanford University introduced the term persuasive technology (PT), which he defined as “a computing system, device, or application intentionally designed to change a person's attitude or behavior in a predetermined way.” He also coined the term “Captology,” which he derived as a partial acronym for Computers As Persuasive Technologies (CAPT-ology), for this area of study. Three international conferences have been held on PT since 2006 and it is expected that PT will become a major research area in behavior change. PT itself is, in fact, not unknown to the field of health behavior change and promotion. Two examples in behavior change that have been around for some times are pedometers for monitoring and promoting walking behavior and the computerized “baby” doll for teen pregnancy education and prevention. Very recently, internet-, GPS/GIS-, cellphone -, and multisensor-based technologies have been used as PT for behavior change and health promotion. Devices such as Nike+iPod shoes, Dance Dance Revolution (DDR) and the Wii have gained the attention of the media and the public. Most of the above efforts and products, however, were not developed and evaluated under the framework of captology. Questions such as “What are the critical characteristics of PT?” “Which (or which set of) persuasive strategy/PT is the most effective in behavior change and health promotion?” “What ethical issues are in PT?” “How should PT be developed for subgroups, especially those with health disparities?” have yet to be addressed. The purpose of this presentation is to provide an overview on persuasive technology: What it is? Why we need it? How can it be designed and implemented? Other critical issues related to PT and its application in health behavior changes will also be discussed along with real-life examples. Keyword(s): health promotion, research, technology