The debate on the nature of the quark-gluon plasma (QGP) has been brought into a sharp focus by the recent data from RHIC at BNL, New York. New models/scenarios have been proposed to explain their features, Lattice QCD can contribute to this debate by providing information of the properties of QGP. After a brief review of what has been achieved so far, I shall present our results on the hadronic screening lengths as another window to glean the properties of QGP.