The observed spectral blue shift of the electroluminescence in quantum well structures on InxGa1-xN is explained on the basis of existence of newfound excitons connected with the electron band structure of this semiconductor. New method for calculation of the electron band structure of multinary compound alloys is developed in the paper. This method takes into consideration that the electron energy depends on both the electron wave vector and the structure of the multinary crystal. The LCAO electron band structure of wurtzite In,Ga1-xN is determined by this method as function of both the electron wave vector and the electron radius vector. New type of exciton called exciton of the ;structure is found on the basis of the electron band structure of wurtzite InxGa1-xN. The binding energy and the hydrogen like energy levels of the excitons of the structure are found. It is found that the movement of the excitons of the structure is possible only by tunneling and that these excitons are localized. It is found that destroying of these excitons has place in their interactions with hetero-junction and the observed spectral blue shift is explained on the basis of electrons and holes of exciton origin generated in this destroying. (C) 2002 Elsevier Science B.V. All rights reserved.