An object of the present invention is to provide a liposome composition containing a liposome having an excellent leakage rate of a nucleic acid analog anticancer agent, and a method for producing the same. According to the present invention, there are provided a liposome composition containing a liposome which (1) contains a nucleic acid analog anticancer agent and in which (2) a content ratio of a lysophospholipid contained in a lipid forming the liposome with respect to a total amount of phospholipids other than the lysophospholipid contained in the lipid forming the liposome is 0.01 mol% to 5 mol% and (3) a nucleic acid analog anticancer agent / lipid ratio is 2 mass% to 10 mass%, and a method for producing the same.
