A practical and efficient protocol for Ag/Ru-cocatalyzed regioselective C-H amination of 8-hydroxyquinoline esters with pyrazoles was developed, This reaction proceeded smoothly via a photoredox-mediated direct C-H/N-H oxidative coupling process. The remarkable features of this reaction include the wide substrate scope, mild reaction conditions and high regioselectivity at the C4 site of the quinolinyl