The present invention addresses the problem of providing a method for causing a poorly water soluble pharmacologically active substance to be included in a liposome with high efficiency. Provided is a composition comprising a lipid having a phosphatidylcholine group a cholesterol compound a lipid having a phosphatidylethanolamine group and a poorly water soluble pharmacologically active substance wherein the lipid having a phosphatidylcholine group the cholesterol compound the lipid having a phosphatidylethanolamine group and the poorly water soluble pharmacologically active substance are contained at a molar ratio of (3 to 8):(2 to 7):(0.1 to 3):(0.001 to 5).
