A total of 30 pieces of Kyosera Injection Port, as a kind of implantable reservoir, was used in 29 cases of liver tumor for an intermittent repeated chemotherapy. Of these 27 cases were actually used between Aug. 1st, 1986 and Aug. 31st, 1989. In this paper we studied the safety of the reservoir. The observation period averaged 259.4 days, with the highest of 760 days and the lowest of 29 days. The injection times averaged 12.7 times, with the maximum of 40 times and the minimum of one. The reservoir was placed under the laparotomy, and the cases which underwent cholecystectomy were 93.1%. 16 cases were treated with intraarterial infusion, and 14 with intraportal infusion. We investigated the complication of Kyosera Injection Port in 27 cases. As a result, there were no complication such as catheter occlusion and infection via catheter. But of 27 cases, 8 cases were recognized a complication, and the rate was 29.6%. Lumbago was noted during infusion chemotherapy in three cases, and on the other hand, there were steatolysis and necrosis of the tissue surrounding the implantation site, a movement of port, a catheter out of vessel, a leakage of the drug, and intraabdominal bleeding after taking off the catheter. But of 8 complication cases, only two cases were not able to inject drug. As a result, the rate of complication was 70.4% in over all. On the other hand, of 27 cases, there were 5 cases which recognized the complication caused by reservoir in itself. The safety rate was 81.5%. In such a circumstance this reservoir was very safe and seemed suitable to the implantable reservoir.