Provided is a composition for external application, which comprises pyrroloquinolinequinone (PQQ) or a pharmaceutically acceptable salt thereof and a surfactant and has a pH value of 4-6. When a surfactant is added to a composition containing PQQ or a salt thereof, the stability of PQQ or the salt thereof is deteriorated significantly. The storage stability of PQQ or a salt thereof in a composition comprising PQQ or the salt thereof and a surfactant can be improved by adjusting the pH value of the composition to 4-6.