Either atropin or Buscopan had been generally used as drugs for a premedication gastrocamera. But these drugs were not enough to subside the side reactions accompanied by insertion of gastrocamera. Therefore, we performed the following experimental procedures on patients to remove the undesirable reactions. The patients were devided into 3 groups (A, B and C group) and all of them were intramusculary treated wtth chlorpromazine at 45 minutes before the insertion of gastrocamera, followed we the subcutaneous injection of 0.3 cc, 0.5 cc and 0.8 cc of pabinal-atropin respectirely. For the local anesthesy of pharynx and hypopharynx, 0.5% solution of T-caine were given for garging in addition that 1% solution of them for appliation. These results were as follows: In the B and C groups salivary secretion, one of the undesirable reactions, was more suppressed. more over the pain accompanied by the insertion was less the other one. (see table 1) on the supression of salivary reaction, the further experimental observations were performed. In this procedure patients were divided into 2 groups, one of the groups was used with injection of 20 mg of Buscopan intramusculary and the other was given of 0.5 cc of pabinal-atropin and 10 mg of C. P. Z., From this, we obtained superior results in the latter regarding as a salivary reaction. (see table II) From these experimental observations, it was assumed that 0.5 cc of the subcutaneous injection of pabinal-atropin and 10 mg of the intramuscular injection of C. P. Z. which were treated before 45 minutes of the insertion, were most suitable for the management of a premedication of gastrocamera.