In this study, the effect of the activities carried out via Web 2.0 tools on the biology education master students' content development self-efficacy beliefs and students' views were examined. The mixed model was used in the study. The study group consisted of 15 students who took the course "Web Supported Material Design in Biology Teaching" in the last three years in the Master's program of Biology Education of a public university in Turkey. The data of the research were obtained through the "Web 2.0 Fast Content Development Self-Efficacy Belief Scale" and an interview form containing 5 open-ended questions. During the implementation process, students developed content with eight web 2.0 tools (Camtasia Studio, Prezi, Thinglink, etc.). As a result of the implementation, it was seen that the self-efficacy belief levels of the students increased. When the students' views were examined, the advantages of web 2.0 tools such as being interesting and entertaining, increasing retention in learning and providing rich content came to the fore. Regarding the limitations of these tools, issues such as lack of internet connection and hardware, technical problems, high cost and time management are highlighted. In addition, suggestions for the effective use of Web 2.0 tools in biology teaching, experiences in daily/business life and views about their favourite tools are also included.