This study aimed to investigate the effect of breathing exercises using a 4-week Chest cage expansion exercise on Respiratory capacity and quality of life in the elderly. The study subjects were 18 elderly people aged 65 years or older living in Gangnam-gu, and the chest cage expansion exercise was performed at N hospital from July 2023 to August 2023. Chest cage expansion exercise was performed for four weeks, and Force Vital Capacity, Forced Expiratory Volume in 1 second, Forced Expiratory Volume in 1 second/Force Vital Capacity, Peak Expiratory Flow, Chest cage expansion test, and quality of life test were checked. One-way Repeated Measures ANOVA was used by using SPSS ver. 22.0 to compare the effect of Chest cage expansion exercise according to time, and a post hoc test was conducted through the Bonferroni test. The study results showed a significant increase in FVC, FEV1, PEF, Chest cage expansion test, and quality of life test at post hoc test (p<.0167). Therefore, chest cage expansion exercises will improve the respiratory function and qualities of life of the elderly, which will help them improve their ability to live daily and achieve life satisfaction.