A NH/3C-SiC heterojunction and a heterostructur of the NH/3C/NH type (N = 2, 4, 6, 8) are consid-ered. Two possibilities are analyzed for heterojunctions, in which a Si or a C is the contact plane of the NH polytype. In this case, the energies of the quasi-local levels in the quantum wells at the interface will be different. With the difference of these energies measured, it is possible to determine the spon-taneous polarization inherent in the NH polytype. In the presence of a spontaneous polarization field, the quasi-local levels in the left- and right-hand quantum wells of the heterostructure have dif-ferent energies. It is shown that, if the heterostructur is placed in an external electric field, it is possible to determine the magnitude of the spontaneous polarization by calculating the different between the energies of these levels. Experimental ways to find by using the suggested theoretical scenario are discussed.