A benzo[h]cinnoline compound of the formula: ##STR1## wherein each of X and Y is hydrogen, halogen, trifluoromethyl, hydroxy, alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms, amino, alkanoylamido having 2 to 4 carbon atoms, nitro, cyano, alkanoyl having 2 to 4 carbon atoms; Ar is phenyl or pyridyl which may be optionally substituted by at least one substituent selected from the group consisting of halogen, trifluoromethyl, hydroxy, alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms, amino, alkanoylamido having 2 to 4 carbon atoms, nitro and cyano; and the bond position indicated by dotted line is single bond or double bond, a method of preparing said compound and a pharmaceutical composition containing said compound.Since these compounds possess high affinity for benzodiazepine receptor and antianxiety activity, they are useful as neutralizers to an excess dose of antianxiety agents or as antianxiety agents.