Electron system properties in heterostructures based on ZnCdHgTe and PbS semiconductors were investigated for the first time. These structures were obtained by liquid phase epitaxy and molecular beam epitaxy. Quasi-two-dimensional electron gas was formed : between metal (lead) and p-type ZnCdHgTe semiconductor in the first case, and in the p-PbS/n-ZnSe heterostructure in the second case. Current-voltage characteristics in the temperature range of 77-293 K were investigated. The main electrical parameters (surface electron state density, space charge region capacitance etc.) in the Anderson-Cherveny-Liou model were estimated. The electron wave functions in the electron gas system and the relevant energy eigenvalues were calculated in the approximation of a triangle potential well.