Let
Ω
⊂
R
N
\Omega \subset R^N
be a bounded domain such that
0
∈
Ω
,
N
≥
3
,
2
∗
=
2
N
N
−
2
,
λ
∈
R
,
ϵ
∈
R
0 \in \Omega , N \geq 3,2^*=\frac {2N}{N-2},\lambda \in R, \epsilon \in R
. Let
{
u
n
}
⊂
H
0
1
(
Ω
)
\{u_n\}\subset H_0^1(\Omega )
be a (P.S.) sequence of the functional
E
λ
,
ϵ
(
u
)
=
1
2
∫
Ω
(
|
∇
u
|
2
−
λ
u
2
|
x
|
2
−
ϵ
u
2
)
−
1
2
∗
∫
Ω
|
u
|
2
∗
E_{\lambda ,\epsilon }(u)=\frac {1}{2}\int _{\Omega }(|\nabla u|^{2}-\frac {\lambda u^2}{|x|^2}-\epsilon u^2)-\frac {1}{2^*}\int _{\Omega } |u|^{2^*}
. We study the limit behaviour of
u
n
u_n
and obtain a global compactness result.