In order to study the effect of spinal nareotics on postoperative pulmonary function and ventilatory reserve after upper abdominal surgery, small preoperative doses of morphine were administrated into the subarachnoidal space and the changes in FVC, FEVi.e., MMEF and FEVi.e./FVC with the SC-20 spirometric computer wer evaluated. The results were as follows: 1) On the 1st day postoperatively FVC of the control group was 56% of the preperative value, 2.94±0.68(1/sec), and that of the morphine group was 66% of the preoperative value, 2.99±0.73(1/sec).(p<0.05) On the 2nd and 3rd day postoperatively the control group was 64% and 65% and that of the morphine group was 82% and 87%. (p<0.05) 2) On the 1st and 2nd postoperative day FEVi.e. of the control group was 52% and 57% of the preoperative value, 2.49±0.43(1/sec), and that of the morphine group was 61%, and 65% of the preoperative value, 2.42±0.68(1/sec). (p<0.05) On the 3rd postoperative day the FEVi.e. of the control group was 65% and that of the morphine group was 80%. (p<0.05) 3) On the 1st and 2nd postoperative day the MMEF of the control group was 56%, and 61% of the preoperative value, 2.45±0.77(1/sec). In the 3rd postoperative day the MMEF on the control group was 63% and that of the morphine group was 78%. (p<0.01) 4) The preoperative FEVi.e./FVC of the control group was 84.3% and that of the morphine group was 78.7%. in the postoperative period, there were no significant differences between the control and morphine group.