An objective of the present invention is to provide compounds having Rho kinase inhibitory activity. The compounds according to the present invention are those represented by formula (I) or pharmaceutically acceptable salts or solvates thereof: Het--X--Z (I) wherein Het represents a monocyclic or bicyclic heterocyclic group containing at least one nitrogen atom, for example, pyridyl or phthalimide; X represents group (i) --NH--C(.dbd.O)--NH--Q1-, group (ii) --NH--C(.dbd.O)--Q2-, wherein Q1 and Q2 represent a bond, alkylene, or alkenylene, or the like; and Z represents hydrogen, halogen, a monocyclic, bicyclic, or tricyclic carbocyclic group, a heterocyclic group or the like, for example, optionally substituted phenyl.