The invention relates to a method for preparing a 
prostaglandin E1 lipid 
microsphere injection of a charging non-homogeneous phase (comprising a water phase, an oil / water interfacial film phase and an 
oil phase) dispersion 
system, of which the surface of the lipid 
microsphere can be charged with positive 
electricity or negative 
electricity. The 
prostaglandin E1 is alprostadil, of which the 
chemical structure comprises a basic skeleton of 20-carbon 
fatty acid with a 5-carbon ring and two side chains, wherein one 
side chain is provided with a hydrophilic 
carboxylic acid group, so that the 
prostaglandin E1 has the characteristic of light surface activity action. By utilizing the characteristic, and according to the formula and the preparation process provided in the invention, the 
prostaglandin E1 has an unique 
drug-carrying mode in a solution of lipid 
microsphere with the non-homogeneous phase dispersion 
system, and the prepared lipid microsphere injection is fundamentally different from an 
alprostadil injection(Kaishi, and is prepared by adopting the technology of the Japanese business corporation LTT Bio-Pharma Co., Ltd. already sold in markets, and the difference lies in that the 
drug-carrying mode is completely different, the content of degradation products in the preparation such as impurities is more than 50 percent lower than that of in the Kaishi, so that the 
prostaglandin E1 lipid microsphere injection and the 
alprostadil injection are fundamentally different. The invention relates to a method for preparing the 
prostaglandin E1 lipid microsphere injection and the 
drug-carrying characteristics thereof in a three-phase 
system; in the formula, 0.0001 to 0.1 weight portion of prostaglandin E1 is used as a drug, the prostaglandin E1 is added with auxiliary materials for medical purpose to prepare the prostaglandin E1 lipid microsphere injection, and the auxiliary materials for medical purpose comprises the following materials in portion by weight: 5 to 20.