The purpose of this article is to introduce and develop a teaching method and process that incorporates quick response (QR) codes and smartphones into field trips for biology classes. The teaching process using QR codes and smartphones consisted of four steps. The first step was the selection of a suitable field study site and identification of species at the site. For this study, a tidal mudflat in Korea was selected and 24 species were identified at the field site. The second step was the generation by the instructor of QR codes for the 24 species, construction of QR code sheets for the species, and installation of a “QR code decoding app” on students' smartphones. In step 3, students explored and identified species at the field study site using the QR code sheets and shared their results with classmates via a social network system (SNS). The final step was the presentation and discussion of results in follow-up classes. The teaching method developed for this study led to active classroom discussion via smartphone social-networking services. Besides detailing the “scan and learn” teaching method and process, the paper offers a quick checklist for teachers and simplified specifics for the creation of a customized and illustrative field-study guidebook that motivates students.