In this paper

the energy levels of polarons in the wurtzite GaN/Al

x

Ga

1-

x

N quantum well structure are studied by using Lee-Low-Pines (LLP) transition. The ground state

first excited state and transition energies from first excited state to ground state are calculated as a function of well width (

L

) and depth (

V

0

). The results indicate that the ground state

first excited state and transition energies rapidly decrease with increasing the well width at smaller

L

but slowly at larger

L

and finally approach to the bulk value of GaN. The ground state

first excited state and transition energies all slowly increase with increasing

V

0

and it is more visible in narrow well. It is also found that the contribution of electron-phonon interaction in wurtzite nitride quantum well structure is very large

the value (about 40 meV) is much larger then that (about 3 meV) in zinc-blende (GaAs/Al

x

Ga

1-

x

As) quantum well structure. Therefore

the contribution of electron-phonon interaction in wurtzite GaN/Al

x

Ga

1-

x

N quantum well structure should be considered when the problem of election state is discussed.