Statistical　surveillance　for　covariance　matrices　has　attracted　increasing　attention　recently.　Many　approaches　have　been　developed　for　monitoring　general　shifts　that　are　arbitrary　deviations,　as　well　as　sparse　shifts　occurring　in　only　a　few　elements.　This　paper　considers　directional　shifts　that　occur　in　only　one　independent　parameter,　which　is　common　if　the　process　is　relatively　stable.　A　directional　covariance　matrix　control　chart　is　proposed,　which　fully　exploits　directional　shift　information　and　borrows　the　strong　power　of　likelihood　ratio　test.　Therefore,　this　chart　provides　a　powerful　tool　for　monitoring　covariance　matrices.　In　addition,　the　proposed　chart　does　not　require　specifying　the　regularisation　parameter,　and　it　enjoys　a　concise　quadratic　form,　thereby　easy　to　implement.　Furthermore,　this　chart　naturally　leads　to　a　diagnostic　prescription　for　identifying　the　shifting　element　in　the　covariance　matrix.　Simulation　results　have　demonstrated　the　efficiency　of　the　suggested　control　chart　and　its　accompanying　diagnostic　scheme.