In this paper, we obtained character formulas of irreducible unitary representations of
U
(
n
,
n
+
1
)
U(n, n+1)
by using Howe’s correspondence and the Cauchy–Harish-Chandra integral. The representations of
U
(
n
,
n
+
1
)
U(n, n+1)
we are dealing with are obtained from a double lifting of a representation of
U
(
1
)
U(1)
via the dual pairs
(
U
(
1
)
,
U
(
1
,
1
)
)
(U(1), U(1, 1))
and
(
U
(
1
,
1
)
,
U
(
n
,
n
+
1
)
)
(U(1, 1), U(n, n+1))
.