Disclosed is a liquid preparation for external application, which has a shortened transdermal absorption lag time and has excellent transdermal absorption properties. Also, disclosed is a liquid preparation for external application, which is less irritative to skin. The problems can be solved by a transdermal liquid preparation containing: (a) propylene glycol in an amount of 40 to 98% by weight； (b) phosphatidylcholine in an amount of 0.1 to 5% by weight； (c) oleyl alcohol and/or isostearyl alcohol in an amount of 0.1 to 10% by weight； and (d) a medicine in an amount of 0.1 to 25% by weight. It is preferred that the transdermal liquid preparation additionally contains an alkanol amine. The alkanol amine is preferably triethanolamine.
