Supercritical parametric wave phase conjugation (SWPC) is used for selection and phase conjugation of harmonic components of a nonlinear incident wave. Amplitude of the phase conjugate wave in a supercritical mode is high enough for acoustic nonlinearity of propagation medium to appear. As a result, in particular, doubled and quadrupled frequencies of the incident wave become available for image formation at the same order of the medium nonlinearity. The improvement of the imaging system resolution because of harmonic analysis of the received acoustic signal and compensation of phase distortions caused by wave phase conjugation were observed simultaneously when propagation medium was inhomogeneous.