An object of the present invention is to provide an agent for promoting proliferation of a meibomian gland epithelial cell and a corneal epithelial cell, as well as provide an agent for treating an ocular disease such as meibomian gland dysfunction or evaporative dry eye. There are provided an agent for promoting proliferation of a meibomian gland epithelial cell or a corneal epithelial cell, containing a PPAR.alpha. or .delta. agonist as an active ingredient, as well as an agent for treating an ocular disease such as meibomian gland dysfunction or evaporative dry eye, containing a PPAR.alpha. or .delta. agonist as an active ingredient.