Organic-inorganic single quantum well with organic heterojunction ITO\SiO2 (60 nm)\MEH-PPV(40 nm)\Alq3 (40 nm)\SiO2 (60 nm)\Al has been fabricated. With the detailed investigation of photoluminescence and electroluminescence of this novel device, the authors found that the permittivity confinement effect and the quantum size effect have obviously an effect on the optical and electrical properties of organic-inorganic quantum well with organic heterojunction. The electroluminescence of organic-inorganic quantum well with organic heterojunction included three different emissions under alternative-current voltages: 410, 510 and 590 nm, which originated from radiative recombination of MEH-PPV, recombination of Alq3 excitons and MEH-PPV excitons respectively.