PURPOSE: To obtain a blood triglyceride depressing agent containing a fat emulsion containing prostaglaiudin E1 as an active component and exhibiting excell. ent sustained releasability, durability, local (focus) accumulation property and storage stability.

CONSTITUTION: This blood triglyceride depressing agent contains a fat emulsion containing prostaglandin E1 or its derivative as an active component. The fat emulsion is preferably a mixture of 5-50%(W/V) of vegetable oil, 5-30 pts.wt. (based on 100 pts.wt. of the vegetable oil) of a phospholipid and a proper amount of water. The agent is preferably used in the form of an intravenous injection and preferably 1-50μg of the agent is injected at a rate of 0.02-0.2ng/kg/min.