We study the quark-gluon mixed condensate which is another chiral order parameter, in SU(3)(c) lattice QCD with the Kogut-Susskind fermion at the quenched level. Using 100 gauge configurations on the 16(4) lattice with beta = 6.0, we measure g<(q) over bar sigma(munu)G(munu)q> at 16 points in each gauge configuration for each current-quark mass of m(q) = 21, 36, 52 MeV. From the 1600 data for each mq, we find m(0)(2) equivalent to g<($) over bar sigma(munu)G(munu)q>/<(q) over bar qq> similar or equal to 2.5 GeV2 at the lattice scale of a(-1) similar or equal to 2GeV in the chiral limit. The large value of g<(q) over bar sigma(munu)G(munu)q> suggests its importance in the operator product expansions in QCD. We also show our preliminary results of g<sigmamunuGmunuq> at finite temperature.