The　isotopic　ages　of　the　main　porphyraceous　granodiorite　at　the　deep　part　of　the　Zijinshan　orefield　of　Fujian　province,　China,　were　dated　by　using　in-site　zircon　SHRIMP　U-Pb　method　and　hornblende　and　potassium　feldspar　40Ar/39Ar　method.　The　206Pb/238U　weighted　average　ages　of　the　zircons　from　three　samples　are　102.8±1.5　Ma　(n=13,　MSWD=0.67),　102.4±1.7　Ma　(n=9,　MSWD=0.73),　100.4±1.8　Ma　(n=12,　MSWD=1.2),　respectively.　The　three　samples　as　whole　yielded　a　weighted　average　age　of　101.8±1.5　Ma　(n=34,　MSWD=1.0),　which　most　likely　represents　the　age　of　crystallization　of　the　porphyraceous　granodiorite.　The　40Ar/39Ar　dating　of　two　hornblende　and　two　potassium　feldspar　samples　yielded　isochron　ages　of　100±11　Ma,　102.2　Ma,　96.3±1.7　Ma,　and　98.5　Ma,　respectively.　Based　on　the　theory　of　mineral　sealing　temperature,　the　cooling　rate　of　the　rocks　of　the　main　porphyraceous　granodiorite　at　the　deep　part　of　the　Zijinshan　orefield　is　estimated　to　be　about　40.7~67.1/Ma　from　crystallization　of　zircon　to　closure　of　hornblende　40Ar/39Ar　system,　116.9~216.3/Ma　from　closure　of　hornblende　40Ar/39Ar　system　to　closure　of　potassium　feldspar　40Ar/39Ar　system.　Both　of　the　estimated　cooling　rates　of　the　rock　are　rather　high.　In　comparison　with　the　paleogeothermal　gradient,　the　pluton　uplift　and　exhumed　3　km　from　crystallization　(101.8±1.5　Ma)　to　the　closure　of　potassium　feldspar　40Ar/39Ar　system　(96.3±1.7　Ma),　suggestive　of　rapid　uplift　and　exhumation　during　this　period.　The　dating　results　show　that　there　is　a　large　batholith　at　the　deep　part　of　the　Zijinshan　ore　field　which　contributed　to　the　porphyry　mineralization.　Single　mineral　40Ar/39Ar　dating　results　provided　meaningful　constraints　on　the　uplift　and　exhumation　of　the　deposit.　©　2016,　Science　Press.　All　right　reserved.