The authors observed functional change of the CBD and the afferent loop with the transit time of Tc-99m-DISIDA scintigram in patients treated by the surgical operation of gastric ulcers and cancer at Busan National University Hospital from June, 1987 to April, 1988. So authors estimated the time between the peak activity of the CBD and the afferent loop (TCA), the half transit time of the CBD activity (t1/2 CBD) and the half transit time of the afferent loop activity (t1/2 A-loop) in 9 patients undergone truncal vagotomy, who have no specific symptoms at 2 to 6 months after the operation, 5 patients undergone the operation without truncal vagotomy, and 7 persons as a control group. The results were as follows: 1) In control group, the mean TCA, t1/2 CBD and t1/2 duodenum were 8.6±9.0 min., 38.7±17.3 min. and 28.6±10.9 min, respectively. 2) In the operation group without truncal vagotomy, the mean TCA, t1/2 CBD and t1/2 A-loop were 10.0±7.1min. 48.2±22.3 min. and 39.4±26.7 min. respectively. 3) In the operation group with truncal vagotomy, the mean TCA, t1/2 CBD and t1/2 A-loop were 15.0±8.7 min., 36.1±16.5 min. and 42.6±24.4 min, respectively. From the above results, we concluded that the transit time of the CBD and the afferent loop is not affected by truncal vagotomy.