The present invention provides an external preparation for skin comprising a phospholipid having an iodine value of 80 to 110, ethanol in an amount of 55 to 83 wt % and water in an amount of 15 to 43 wt %, which is improved in it's preparation stability by suppressing an increase in an acid value of phospholipid. The present invention also provides an external preparation for skin which is improved in percutaneous absorption of medically effective ingredient(s). The present invention provides further a method for suppressing an increase in an acid value of phospholipid by comprising phospholipid having high iodine value and high concentration of ethanol and water, as well as a method for improving percutaneous absorption of medically effective ingredient(s) in external preparation for skin.