Abstract Marital satisfaction is an important concept with a multidimensional structure that has a significant role in maintaining and strengthening the family foundation. The purpose of this study is to predict marital satisfaction based on assertiveness and emotional expressiveness concerning the mediating role of quality of life in female athletes and non-athletes. The study is a descriptive-correlational one. The statistical population of the study included all athletes and non-athletes married women living in Tehran, of whom 200 of them (100 individuals in each group) were selected using a convenient sampling method. Data collection tools included Enrich Marital Satisfaction Questionnaire (1989), The Quality of Life of the World Health Organization (1996), Gambrill and Ritchie Assertiveness (1975), and the Emotional Expressiveness of King and Emmons (1990). The collected data were analyzed using descriptive and inferential statistics using SPSS-22 and AMOS software. Path analysis results found that the proposed model has a good fit and the quality of life mediates the relationship of assertiveness and emotional expression with marital satisfaction. The marital satisfaction of female athletes was significantly higher than the marital satisfaction of non-athletes. The findings of the current study show the importance of variables related to marital satisfaction and the effects of sports activities on women’s marital relationships.     Keywords Marital Satisfaction, Quality of Life, Assertiveness, Emotional Expressiveness, Women.   Introduction One of the most important factors of women's growth and development is their success rate in marriage and marital satisfaction (Logan, 2018). Marital satisfaction is defined as a person's general attitudes or feelings towards his or her spouse and relationship (Bachem, Levin, Zhou, Zerach, & Solomon, 2018). The married life of female athletes has certain characteristics compared to non-athlete females. According to Harris (2006), Women athletes have the challenging task of coping with two very emotional situations at the same time: marital relationship and athletic activity. One of the most important social skills, the lack of which causes problems in marital relationships and affects marital satisfaction, is assertiveness and emotional expression (Dagan et al., 2014; Maheshwari, & Gill, 2015). Assertiveness or assertive behavior is an important social skill that enables a person to deal properly with family issues, to evaluate themselves positively in terms of cognition and emotion, and to enjoy supportive relationships and high marital satisfaction (Alberti, & Emmons, 2017). Emotional expression is defined as the ways of verbal and non-verbal expression that a person shows in emotion-focused situations (Yedirir, & Hamarta, 2015). Emotional expression is an important component of the emotional structure of the family that affects marital relationships (Konishi, Froyen, Skibbe, & Bowles, 2018). Furthermore, quality of life is one of the important variables that affect the individual aspects in addition to interpersonal and marital relationships (Laily, Kania, Ilmi, & Marlinae, 2018). Quality of life is people's perception of their life situation in the context of the culture and value system in which they live. Quality of life is a combination of positive emotions and positive performance that can predict marital satisfaction (Nofal, & Ha, 2019).  This study aims at predicting marital satisfaction based on assertiveness and emotional expressiveness concerning the mediating role of quality of life in female athletes and non-athletes.   Methods In terms of methodology, the present study was descriptive and correlational and the statistical population consisted of both married female athletes and non-athletes in Tehran in 1398. A sample of 200 individuals (100 people in each group) was selected using the convenience sampling method; The questionnaires were distributed among female athletes in Azadi Sports Complex. Non-athlete samples were also chosen from the local communities and public places of District 6 of Tehran. Literacy, being married, willingness to participate in research, and at least one year of professional sports experience in the category of female athletes was required for joining the study. In addition to descriptive indicators, inferential tests of the structural equation model and t-test were used to analyze the data collected using SPSS-22 and AMOS software. Data was collected using Enrich Marital Satisfaction, Quality of Life, and Emotional Expression Questionnaires.   Results The path coefficient test showed that the standardized path coefficient was a direct effect of emotional expression and quality of life on marital satisfaction at the level of 99% confidence however, the direct effect of assertiveness on marital satisfaction was not significant (p> 0.05). The results of Sobel test results showed that assertiveness indirectly affected marital satisfaction through quality of life (p , 9(2), 60-73. [Text in Persian] Momeni Javid, M., & Shoaakazemi, M. (2011). 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