The excretion of T-1220 in bile was evaluated in 4 patients with biliary tract diseases. The bile was collected for 6 hours after intravenous injection of T-1220. The maximal concentration in bile was 1,600 mcg/ml at 0.5 approximately 1 hour after administration of 1 g of T-1220 to 1 case. In 3 cases treated with 2 g, the maximal concentration was 155 approximately 1,115 mcg/ml at 2 approximately 3 hours after administration. Total excretion rates in bile after 0 approximately 6 hours were 0.5 approximately 7.2%. T-1220 was applied clinically to 3 patients with biliary tract infections. Clinical results obtained were good in all cases. No side effect was observed in all cases.