Provided is a means capable of efficiently growing corneal endothelial cells and a means of stably supplying a corneal endothelial preparation. An agent for promoting adhesion of a corneal endothelial cell, containing a Rho kinase inhibitor, a culture medium for a corneal endothelial cell, containing a Rho kinase inhibitor, a solution for preservation of cornea, containing a Rho kinase inhibitor, and a method of producing a corneal endothelial preparation, including a step of culturing the corneal endothelial cell using the above culture medium.
