Introduction: Chest wall expansion is defined as a circumferential measurement of chest wall ability from rushing through in hellion only. Chest expansion measurement are used to assess a patients baseline statue treatment effectiveness and progression of disease with regards to chest wall moiety and respiratory muscle function. Chest expansion is used as a measurement tool in research or in clinical practice. At present, research expansion is the method for processing the involvement of chest wall particularly controverter and costotransverse joints for diagnostics and monitoring progression as a part of routine assessment. Chest compression is also affected by age, sex, body compotation, and other geography parameters. Objectives of the study: To find out the normal values for chest expansion at all the three levels of chest in healthy subjects of 20-40 years of age group. • Manubrium sterni • Xiphisternum • 2 inches above the umbilicus Methodology: The study of chest expansion is done on healthy normal individual with the mean age of 30 years (20-40 years). The study was conducted at Adesh Hospital and Research Centre, Sri Muktsar Sahib and In Malout for 21 days. A sample of 10 subjects and those fulfilling the inclusion and exclusion criterion were included in the study. Subjects were randomly assigned to 2 groups. Results: The comparison of subjects just expansion for age group 20-30 to 30-40 showed respective mean difference. The current study shows a positive correlation between males and BMI and females and BMI., for age group 20-40 increase in BMI which is within normal range showed positive correlation. Discussion and conclusion: There are significant effect of abdominal breathing exercise in increasing chest expansion at all three levels.