Due to the novelty of COVID-19 disease and the importance of determining the most important factors related to the health behaviors of people, this study was done to determine the structures of Health Belief Model (HBM) following the COVID-19 outbreak. This was an analytical-cross sectional study conducted in 2020. The statistical population included all users of Iranian social networks, of which 385 people participated in this study. Participants were selected using convenience sampling. The data collection tool was a researcher-made questionnaire. In this study, demographic variables (being a student, age, reporting violations in health protocols (RVHP), marital status, level of education, gender, and the number of children) were independent variables and constructs of the HBM were dependent variables. Data analysis software was SPSS 16. Data were analyzed using Mann-Whitney U and Kruskal-Wallis tests. The mean age of participants was 30.11 years. There was a significant difference between the perceived susceptibility of being a student (p=0.02), age (p=0.01), and RVHP (p=0.005). There was also a significant difference between the perceived severity with marital status, being a student, age (P<0.001), RVHP (p=0.04), and level of education (p=0.01). There was also a significant difference between perceived benefits with marital status (p=0.04), RVHP (p=0.01), and being a student (P<0.001) and perceived barriers with gender and number of children (p=0.03). There was also self-efficacy with RVHP (p=0.005). This study demonstrated the effectiveness of HBM constructs in determining the structures of HBM following the COVID-19 outbreak. Therefore, the HBM seems helpful as a framework for designing interventional programs for improving health behaviors among people during the COVID-19 pandemic.