The purpose of this invention is to provide a method with which it is easy to perform screening for an agent that proliferates or an agent that minimizes the reduction in MCSP-positive basal epidermal stem cells. Provided is a screening method for a laminin 511 expression promoter, which takes the expression of laminin 511 as an indicator. Also provided is an agent for improving skin barrier function, elasticity, hydration and inflammation, said agent including at least one extract selected from among a group consisting of brown algae, red algae and green algae.
