We study the charmonium correlators in the deconfined phase, as well as atT<Tc,in two viewpoints. One is an analysis of correlation between quark and antiquark in the finite temperature lattice QCD at the quenched level. The result implies that the correlation is so strong that the quark and antiquark still tend to stay together even atT≃1.5Tc.On the other hand, the potential model analysis, the second approach, results in the existence of no bound state atT≃1.2Tc.The static quark potential obtained in lattice simulation is used in the latter analysis. The change of the bound state energy belowTcis also studied. ©2001 American Institute of Physics.