Sports is the most important part of activities in children and can improve physical fitness for the children. Respondents in this study are children who participate in sports programs in a sports club, especially swimming and running from the Special Region of Yogyakarta in February-March 2020. This study aims to determine the relationship between Sport effectiveness activities with quality of life and cardiovascular function in children. The method used was quantitative with cross-sectional correlation description design. Data collection techniques namely by distributing questionnaires specifically quality of life and measuring cardiovascular function using the Vo2Max beep test. Data were collected using a purposive method, with a total number of respondents who followed were 76 children aged 5-14 years. The number of male children were 35 children (46.1%) and women were 41 children (53.9%). The results of this study indicated that there was a relationship between the intervention "sport effectiveness" with quality of life in children (p-value = 0.009), with cardiovascular function (p-value = 0.036). it was concluded that the more sports activities (sport effectiveness) can improve the quality of life of children which consists of emotional, social, physical and school functions and improve cardiovascular function