An object of the present invention is to provide an infusion preparation in which the Maillard reaction between an amino acid and a reducing sugar does not occur during storage and the size of fat particles in the fat emulsion does not increase during storage, and in which various types of vitamins can be incorporated in a stable manner, in spite of the fact that it is a two-chamber infusion preparation. Furthermore, even if only one of the infusions (of the infusion preparation) is administered, the patient is unlikely to develop hyperkalemia, vascular pain, or phlebitis. The present invention provides an infusion preparation containing two chambers separated by a partition that can be communicably opened, wherein a first chamber contains a first-chamber infusion containing a sugar and a fat emulsion, a second chamber contains a second-chamber infusion containing an amino acid and an electrolyte, the first-chamber infusion is substantially free of potassium, and has a relative osmotic pressure of 2.0 to 3.0, the second-chamber infusion has a potassium concentration of 40 mEq/L or less and a relative osmotic pressure of 2.5 to 3.5, and a mixture of the first- and second-chamber infusions has a potassium concentration of 16 mEq/L or more as measured upon communicably opening the partition.