It is suggested that upper respiratory obstruction from whatever source may cause various changes in the normal mechanics of lung. So we have measured the changes of arterial blood gas on 30 patients without history of cardiopulmonary disease, who were performed anterior nasal packing after initial nasal surgery and investigated the effects of nasal packing to pulmonary function. The results were as follows ; 1) In the changes of PaO₂, PaO₂ was decreased by 3.55 mmHg during nasal packing state. 2) In the changes of PaCO₂, PaCO₂ was increased by 1.61 mmHg during nasal packing state. 3) In the changes of SO₂, SO₂ was decreased by 1.1% during nasal packing state. 4) In the changes of pH, there was no significant difference between before and after nasal packing state. 5) Patients revealed no signs and symptoms by changes of PaO₂ and PaCO₂ during nasal packing state but we think that we must give special attention during nasal packing especially in patients with history of cardiopulmanary disease.