Quantum　correlations　(including　entanglement　and　quantum　discord)　of　two　qubits　symmetrically　coupled　to　the　surrounding　XY　spin　chain　in　the　presence　of　a　transverse　magnetic　field　are　studied.　We　investigate　the　dynamic　evolution　of　the　quantum　correlations　of　the　two　qubits　when　the　surrounding　spin　chain　is　in　the　thermal　equilibrium　state.　Numerical　results　show　that　the　thermal　effects　can　accelerate　the　decay　process　of　the　quantum　correlations　if　the　initial　state　of　the　composite　system　is　not　in　the　decoherence　free　space.　When　the　temperature　is　high　enough,　the　quantum　phase　transition　driven　by　the　external　magnetic　field　completely　disappear.