I studied on absorption and excretion of cephaloridine. Cephaloridine was administered intravenously to 5 healthy volunteers weighing 65 kg to 83 kg, and the blood levels were measured. A cross over test subjecting 2 grams intravenous drip infused for 1 hour against the same dose for 2 hours were performed after 1 week interval. The disposition of cephaloridine was estimated by applying one-compartment model which was scaled from YOKOKAWA & HULET PACKARD'S disc top computer. Pharmacokinetic parameters are as followings: 1 hour d.i.v.: Kel 1.410 (hr-1), Vd 9.629(L), T 1/2 30.290 (min.) 2 hours d.i.v.: Kel 0.876 (hr-1), Vd 21.106(L), T 1/2 49.372 (min.).