Background & Aims: : Adolescence is a period in which many healthy and unhealthy habits are formed and spread to the next periods of life, and since during this period, healththreatening behaviors increase, adolescents are at risk of many health-threatening behaviors including increased food intake, decreased physical activity, and increased developmental vulnerability. Therefore, a health-promoting lifestyle in teenagers is one of the best ways that they can maintain and improve their health. Health-promoting behaviors are part of daily life activities that create a set of individual happiness, values, and well-being. A healthy lifestyle is a balanced life in which a person consciously makes healthy choices in different areas. Health promotion includes behaviors during which a person should have proper nutrition, exercise regularly, avoid harmful behaviors, protect against accidents, detect signs of illness in time in the physical dimension, control emotions, feelings, and thoughts, and cope with It deals with stress and problems in the mental dimension, independence, adaptability and modification of interpersonal relationships in the social dimension. Therefore, the type of interpersonal relationships and, as a result, the emotional system that governs the family structure and interpersonal relationships, affects the mental health of a person, because this emotional system is the ability to separate and differentiate oneself from others on a cognitive and emotional level. The purpose of the present study was to present a structural model for predicting health-promoting lifestyle in teenage girls based on self-differentiation and interpersonal sensitivity with the mediating role of social support. Methods: The research method was descriptive and correlation type using structural equations. The statistical population in this research was made up of all high school female students in Yazd who were studying in theoretical fields (humanities, experimental sciences and mathematics) in the academic year of 1402-1401. 4 schools from district one and 4 schools from district two of Yazd city (8 schools in total) and from each school three classes from among mathematics, experimental and humanitarian fields (24 classes in total) were selected and in each class the questionnaire was randomly distributed to 15 students were given to complete. Finally, due to the non-response of a number of participants and the missing questionnaires, the analyzes were performed on 340 samples. The measurement tools in this research were Walker's health-promoting lifestyle (1987), perceived social support by Zammit et al. (1988), self-differentiation by Skowron and Smith (2003), and Boyce and Parker's (1989) interpersonal sensitivity. Data analysis was done using Pearson correlation and path analysis to investigate causal relationships between variables. Results: The results of the fit of the proposed model indicated a good fit of the model with the data. The direct coefficients of the model showed that self-differentiation (P<0.001, β=0.203) and perceived social support (P<0.001, β=0.259) have a significant positive effect on healthpromoting lifestyle, and interpersonal sensitivity on style Health-promoting life has a significant negative effect (P<0.001, β=-0.309). Also, with the inclusion of perceived social support variable into the model, the indirect effect of self-differentiation and interpersonal sensitivity on health-promoting lifestyle became -0.0814 and -0.0335, respectively. Conclusion: In explaining this finding, it can be stated that interpersonal sensitivity (emotional and social) is the skill of evaluating others' abilities, states, and traits through their non-verbal signs, and people who have these characteristics are disturbed in interpersonal relationships, regardless of real criticism or not. They are sensitive to accepting and changing their behavior to follow others' expectations, and as a result, they experience dysfunctional interpersonal relationships to a greater extent. Interpersonal sensitivity can cause individual isolation and increase the feeling of social loneliness because people with high interpersonal sensitivity suffer more from pessimism, mistrust, and a hostile view of the world, and as a result, experience social isolation and reduced benefits from social support. On the other hand, they are radically changing their behavior to suit others to minimize the risk of criticism and rejection. Therefore, teenagers in stressful situations may use it as a tool to reduce their mental pressure, which leads to a decrease in their desirable lifestyle. As a result, if teenagers have characteristics that can receive the necessary social support, this support will make them reduce the number of weaknesses caused by separation anxiety and fragile self-esteem and adjust their interpersonal relationships according to their needs. These relationships further satisfy the need for approval and minimize the fear of rejection and criticism, and during a cycle, this model can strengthen the possibility of promoting a desirable lifestyle. In general, people with differentiation and interpersonal sensitivity problems have difficulty in relating to others and maintaining intimate relationships and tend to cut off communication with others, as a result, they probably receive less social support from others. On the other hand, social support can improve problems related to Psychological disorders, and problems play a moderating role. As a result, a person who has high social support is not easily involved in the process of social comparison in the process of non-differentiation, interpersonal sensitivity, or sensitivity to rejection, and it seems that social support can play a mediating role in the relationship between self-differentiation and interpersonal sensitivity with health-related lifestyle.Therefore, adolescents with differentiation and interpersonal sensitivity problems have difficulty in maintaining intimate relationships with others and tend to cut off communication with others, as a result of which they receive less social support from others and the lack of social support causes maladaptive behaviors and Health decreases in these teenagers. [ABSTRACT FROM AUTHOR]