The purpose of this research was to study the perceptions and behaviors of Iranian users in the face of the spread of fake news on Instagram and Telegram social networks. The research method was a survey and the data collection tool was an online questionnaire. The statistical population includes Iranian users who consume social media "Instagram and Telegram" to receive news. The sample size was determined using power analysis, which included 400 people (234 women and 166 men). To determine the validity of the questionnaire, face validity was used and Cronbach's alpha (0.89) was used to determine the reliability of the questionnaire. The findings of the research showed that the expansion of information, media literacy in detecting the spread of fake news and prescriptive expectation from social media significantly predict trust and distrust towards "Instagram and Telegram", which in turn influence the intensity of Iranian users' use of information platforms. Puts. The results of factor analysis showed that information-based characteristics and user characteristics significantly affect trust and distrust, but between the two distinct constructs of trust and distrust, they are important mediators through which the spread of fake news affects users' use.