Physical activity of adolescent girls has important benefits and consequences for them, so that it is also vital to increase the health of society; although following the guidelines of the World Health Organization; the prevalence of inadequate physical activity is very high among Iranian women. Therefore; the purpose of this study was to qualitatively study how Iranian adolescent girls' physical activity works from their own perspective using the paradigm pattern. The methodology of research was Grounded Theory, systematic approach. The study population was Iranian girls aged 18-15 years who had regular physical activity. Sampling method was theoretical sampling method and theoretical saturation was obtained after conduct 22 semi-structured interviews with Iranian adolescent girls and review literature. The data analysis methods were continuous questions and comparison. Findings showed: personal motivations, parents, and promoters are causal conditions; sports facilities, society conditions, trainer and security and safety are the context conditions; physical activity of Iranian adolescent girls is a axial category; cultural problems, mismanagement, limitations, insecurity and unsafe, femininity problems, lack of facilities, not having a good trainer and financial problems are interfering or moderating conditions; competitive sports and non-competitive exercises are routine behaviors or actions / reactions; and health, familiarity with the sports industry, improving ethics and behavior and communication, preventive and therapeutic, getting reward, enriching leisure time and body beauty are the main consequences of physical activity of Iranian adolescent girls in the paradigm pattern.