This study is done to have preservice science teachers chance to implement inquiry before expecting them to implement inquiry in their classrooms and to develop the preservice science teachers' inquiry skills and self-efficacy of science. The study group is composed of preservice science teachers who chose the 2nd grade Biology Laboratory course at Firat University Faculty of Education. The study group consists of 11 male and 55 female male, a total of 66 preservice science teachers. In the study, partially mixed concurrent equal status design is used. Qualitative data were obtained from preservice teachers' evaluation reports and quantitative data were obtained from science self-efficacy scale. The study was carried out during the fall and spring semesters for a total of eight months. Preservice teachers participated in structured, guided and open inquiry applications respectively. The preservice teachers prepared the results of their studies and shared them with their peers in the other groups. Preservice teachers have written three evaluation reports throughout the process. The application of inquiry applications respectively and the fact that the preservice teachers take part in the process like a student in these applications contributed to the science self-efficacy of the preservice teachers.