It is well known that there is an adverse effect of long-term cigarette smoking on pulmonary function. Therefor we attempted to consider the vital capacity for position changes in a smokers and non-smokers. The pulmonary functions on sitting and supine positions were measured in 28 young healthy students fer the change of vital capacity. Forced expiratory flow-volume curve were performed sitting position and supine position and smoking. The results were summarized as follows; 1) The spirometric values(VC, FVC, FEV$_{1}$) were progressively decreased from sitting position to 30minutes after supine position in a non-smoking group(p<.05). 2) The VC, FVC. FEV$_{1}$, FEF25 ${sim}$ 75% were decreased from sitting position to 30minutes after supine position in a smoking group(p< .01). The PEF and FEF25% were decreased from supine position to after smoking(p< .05). 3) non-smoking group and smoking group not showed significant change(p> .05). But the spirometric values were more decreased nonsmokers than smokers.