For the purpose of studying the thermal conductivity of comet ice nucleus surfaces dust crust we have carried out the laboratory experiments on the cometary nucleus models. The experiments were carried out under the conditions close to those at the heliocentrical distances from 1 to 3 A.U. The ice lUO which contained the particles of quartz, graphite, nickel and organic substances DL-alanin, DL-treonin, L-valin has been studied, The dust matrices 5-15 mm in thickness have been formed imder the ice sublimation irradiated witli a light beam. In most cases the effective thermal conductivity of the matrices which included sublimation products diffused in them is one or two orders less than that of H^2O.