The stability and compatibility of fat-soluble vitamin injections (II) (containing vitamin A, D2, E and K1) combined with 10% lipid emulsion injection, 5% glucose injection or 0.9% sodium chloride injection were investigated to provide the evidence for rational use.A high performance liquid chromatog. (HPLC) method was used for determining the changes of vitamin A, E and K1 contents in fat-soluble vitamin injections (II) mixed with three infusions, resp.The appearance, emulsion and colority of the injections were observedAfter mixed for 6 h, the appearance of the injections had no change, and the particle size of emulsion droplet was stable relatively.The contents of vitamin A, E and K1 in the injections decreased gradually with the prolonging of the storage time.The contents of these vitamins were stable relatively in the injections mixed with 10% lipid emulsion injection and 5% glucose injection as compared with 0.9% sodium chloride injection.It indicated that the stability of the fat-soluble vitamin injections (II) combined with 10% lipid emulsion injection or 5% glucose injection could be met the clin. requirement.