This study is an educational randomized controlled trial. The purpose of this study is to determine the effect of educational intervention based on protection motivation theory on oral health literacy promotion. 180 students are selected by a multistage cluster sampling from four secondary schools of the zone 2 and 4 of Shiraz education after elimination of special schools (gifted, non-profit and exceptional) and assign into experimental and control groups. The data is obtained by using oral health literacy and protection motivation theory questionnaire before and after the educational intervention. Inclusion criteria are being female students studying at ninth grade of high school in Shiraz and willingness to participate in the study and exclusion criteria are unwillingness to continue participating in research, absence in the pre-test or post-test, absence of more than one session in educational classes and incomplete filling of questionnaires. Educational intervention include four educational sessions of 45 to 60 minutes once a week based on booklet " be the best friend of your teeth" Which has been prepared by reviewing of the literature and the results of pre-test questionnaire analysis and are perform by lecture, question and answer, group discussion, role playing, video playback, training booklet and poster in intervention group. Primary research outcomes are oral health literacy, behavior and teeth plaque index, and secondary outcome are Protection Motivation Theory components (perceived vulnerability, perceived severity, self-efficacy, response efficacy and response costs) and knowledge.