This paper studies the nature of changes in extinction spectra when changing the core/shell size ratio in spherical and ellipsoidal (prolate and oblate) gold-copper sulfide (Au-CuS) core-shell nanoparticles. The obtained results are analyzed to establish the regularity of changes in the nanoshells extinction spectra, which can be used to develop devices based on them for different applications. The plasmon properties of spherical and ellipsoidal Au -CuS nanoparticles with different sizes were determined. It is established that the intensity of the extinction cross-section of spherical nanoshells strongly depends on the ratio between the thickness of the core and the shell. It is possible to configure the plasmon properties of oblate and prolate ellipsoidal core-shell nanoparticles by changing the core and shell thickness in both directions. Thus, the results of the study suggest that Au-CuS nanoparticles can be used as potential elements of various sensitive sensors.