Purpose : The purpose of this study was to analysis on diaphragm thickness and lung function of stroke patients by walking ability. Methods : We recruited thirty-five adults after stroke(20 male, 15 female) for our study. The subjects were divided into two groups; independent walking group(11 male, 9 female) and non-independent walking group(9 male, 6 female). Assessment of diaphragm thickness was performed using ultrasound in B-mode with a 7.5 MHz linea probe. During the experiment, the subject was seated in the chair. All subjects performed maximal expiratory flow maneuvers using a spirometer in order to determine the forced expiratory volume in 1 second ($FEV_1$), forced vital capacity(FVC), peak expiratory flow(PEF) and $FEV_1$/FVC. Chest expansion was measured with a tape-measure placed circumferentially around the chest wall at the xiphoid process. The collected data analyzed by independent t-test. Results : The diaphragm thickness were significant differences between the independent walking and nonindependent walking group. Values of forced vital capacity, forced expiratory volume at one second, peak expiratory flow in pulmonary function tests were significant differences between the independent walking and non-independent walking group. However, chest expansion were not significant differences in both of the group. Conclusion : This study showed that walking ability of stroke patients have influenced on diaphragm thickness and pulmonary function.