diff --git a/releasenotes/notes/fix_test_for_Qiskit0.45.2-e0544949be8e77fb.yaml b/releasenotes/notes/fix_test_for_Qiskit0.45.2-e0544949be8e77fb.yaml
new file mode 100644
index 0000000000..db24067919
--- /dev/null
+++ b/releasenotes/notes/fix_test_for_Qiskit0.45.2-e0544949be8e77fb.yaml
@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    Fixes test cases failed due to upgrade of Qiskit.
+
+    Removed importing Aer from qiskit.
+
+    QuantumCircuit.diagonal was deprecated, using circuit.library.Diagonal instead
diff --git a/test/benchmark/vqe_application.py b/test/benchmark/vqe_application.py
index fc4e0d91f8..fb94168e8c 100644
--- a/test/benchmark/vqe_application.py
+++ b/test/benchmark/vqe_application.py
@@ -16,13 +16,13 @@
 import numpy as np
 import multiprocessing
 from time import time
-from qiskit import Aer
 from qiskit.aqua.algorithms import VQE
 from qiskit.aqua.components.optimizers import SLSQP
 from qiskit.chemistry.applications import MolecularGroundStateEnergy
 from qiskit.chemistry.components.initial_states import HartreeFock
 from qiskit.chemistry.components.variational_forms import UCCSD
 from qiskit.chemistry.drivers import PySCFDriver, UnitsType
+from qiskit_aer import AerProvider
 
 
 class UCCSDBenchmarkSuite:
@@ -67,7 +67,7 @@ def cb_create_solver(
                 optimizer=SLSQP(maxiter=5000),
                 max_evals_grouped=256,
             )
-            vqe.quantum_instance = Aer.get_backend("qasm_simulator")
+            vqe.quantum_instance = AerProvider.get_backend("qasm_simulator")
             vqe.quantum_instance.backend_options["backend_options"] = {
                 "max_parallel_experiments": threads,
                 "method": method,
diff --git a/test/terra/backends/aer_simulator/test_truncate.py b/test/terra/backends/aer_simulator/test_truncate.py
index 5963143580..eb98b10546 100644
--- a/test/terra/backends/aer_simulator/test_truncate.py
+++ b/test/terra/backends/aer_simulator/test_truncate.py
@@ -9,7 +9,7 @@
 AerSimulator Integration Tests
 """
 from ddt import ddt
-from qiskit import transpile, QuantumCircuit, Aer
+from qiskit import transpile, QuantumCircuit
 from qiskit.providers.fake_provider import FakeQuito
 from qiskit_aer.noise import NoiseModel
 from test.terra.backends.simulator_test_case import SimulatorTestCase, supported_methods
diff --git a/test/terra/reference/ref_diagonal_gate.py b/test/terra/reference/ref_diagonal_gate.py
index 72f506b9c1..00b49e8072 100644
--- a/test/terra/reference/ref_diagonal_gate.py
+++ b/test/terra/reference/ref_diagonal_gate.py
@@ -17,10 +17,7 @@
 
 import numpy as np
 from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister
-
-# Backwards compatibility for Terra <= 0.13
-if not hasattr(QuantumCircuit, "diagonal"):
-    QuantumCircuit.diagonal = QuantumCircuit.diag_gate
+from qiskit.circuit.library import Diagonal
 
 
 def diagonal_gate_circuits_deterministic(final_measure=True):
@@ -41,7 +38,7 @@ def diagonal_gate_circuits_deterministic(final_measure=True):
         for diag in [arg, np.array(arg), np.array(arg, dtype=float), np.array(arg, dtype=complex)]:
             circuit = QuantumCircuit(*regs)
             circuit.h(qubit)
-            circuit.diagonal(list(diag), [qubit])
+            circuit.append(Diagonal(diag), [qubit])
             circuit.h(qubit)
             if final_measure:
                 circuit.barrier(qr)
@@ -53,7 +50,7 @@ def diagonal_gate_circuits_deterministic(final_measure=True):
     for diag in [arg, np.array(arg), np.array(arg, dtype=float), np.array(arg, dtype=complex)]:
         circuit = QuantumCircuit(*regs)
         circuit.h(qr)
-        circuit.diagonal(list(diag), qr)
+        circuit.append(Diagonal(diag), qr)
         circuit.h(qr)
         if final_measure:
             circuit.barrier(qr)
@@ -64,7 +61,7 @@ def diagonal_gate_circuits_deterministic(final_measure=True):
     for diag in [np.array([1, 1, 1, np.exp(-1j * np.pi / k)]) for k in [10, 100, 1000, 10000]]:
         circuit = QuantumCircuit(*regs)
         circuit.x(qr)
-        circuit.diagonal(list(diag), qr)
+        circuit.append(Diagonal(diag), qr)
         if final_measure:
             circuit.barrier(qr)
             circuit.measure(qr, cr)