The influence of the polarization-induced electric field and other parameters on the subband structure in AlxGa1-xN/GaN coupled double quantum wells (DQWs)has been studied by solving the Schr(o)dmger and Poisson equations self-consistently. It is found that the polarization effect leads to an asymmetric potential profile of A1xGa1-xN/GaN DQWs although the two wells have the same width and depth.The polarization effect also leads to a very large Stark shift between the odd and the even order subband levels that can reach 0.54eV.Due to the polarization-induced Stark shift,the wavelength of the intersubband transition between the first odd order and the second even order subband levels becomes smaller,which is useful for realization of optoelectronic devices operating within the telecommunication window region.