diff --git a/monasca_common/tests/test_alarm_expression.py b/monasca_common/tests/test_alarm_expression.py
new file mode 100644
index 00000000..7d64d5af
--- /dev/null
+++ b/monasca_common/tests/test_alarm_expression.py
@@ -0,0 +1,153 @@
+# (C) Copyright 2016-2017 Hewlett Packard Enterprise Development LP
+# Copyright 2019 Fujitsu LIMITED
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import pyparsing
+
+from monasca_common.expression_parser import alarm_expr_parser
+from oslotest import base as oslotest_base
+
+
+class TestAlarmExpression(oslotest_base.BaseTestCase):
+
+    good_simple_expression = "max(cpu.idle_perc{hostname=fred}, 60) <= 3 times 4 OR \
+                             avg(CPU.PERCENT)<5 OR min(cpu.percent, deterministic) gte 3"
+
+    def test_good_expression(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual(3, len(sub_exprs))
+
+    def test_fmtd_sub_expr(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.fmtd_sub_expr_str for x in sub_exprs],
+                         ['MAX(cpu.idle_perc{hostname=fred}) <= 3.0 times 4',
+                          'AVG(CPU.PERCENT{}) < 5.0', 'MIN(cpu.percent{}) gte 3.0'])
+
+    def test_dimensions_str(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.dimensions_str for x in sub_exprs], ['hostname=fred', '', ''])
+
+    def test_function(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.func for x in sub_exprs], ['max', 'avg', 'min'])
+
+    def test_normalized_function(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.normalized_func for x in sub_exprs], ['MAX', 'AVG', 'MIN'])
+
+    def test_metric_name(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.metric_name for x in sub_exprs],
+                         ['cpu.idle_perc', 'CPU.PERCENT', 'cpu.percent'])
+
+    def test_normalized_metric_name(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.normalized_metric_name for x in sub_exprs],
+                         ['cpu.idle_perc', 'cpu.percent', 'cpu.percent'])
+
+    def test_dimensions(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.dimensions for x in sub_exprs], ['hostname=fred', '', ''])
+
+    def test_dimensions_as_list(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        print([x.dimensions_as_list for x in sub_exprs].__str__())
+        self.assertEqual([x.dimensions_as_list for x in sub_exprs].__str__(),
+                         "[(['hostname=fred'], {}), [], []]")
+
+    def test_operator(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.operator for x in sub_exprs], ['<=', '<', 'gte'])
+
+    def test_threshold(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.threshold for x in sub_exprs], [3.0, 5.0, 3.0])
+
+    def test_period(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.period for x in sub_exprs], [60, 60, 60])
+
+    def test_periods(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.periods for x in sub_exprs], [4, 1, 1])
+
+    def test_deterministic(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.deterministic for x in sub_exprs], [False, False, True])
+
+    def test_normalized_operator(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.normalized_operator for x in sub_exprs], ['LTE', 'LT', 'GTE'])
+
+    def test_id(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        self.assertEqual([x.id for x in sub_exprs], [None, None, None])
+
+    def test_set_id(self):
+        expression = self.good_simple_expression
+        sub_exprs = alarm_expr_parser.AlarmExprParser(expression).sub_expr_list
+        for x in sub_exprs:
+            x.id = 88
+        self.assertEqual([x.id for x in sub_exprs], [88, 88, 88])
+
+    def _ensure_parse_fails(self, expression):
+        parser = alarm_expr_parser.AlarmExprParser(expression)
+        self.assertRaises(
+            (pyparsing.ParseException,
+             pyparsing.ParseFatalException),
+            getattr, parser, "sub_expr_list")
+
+    def test_incomplete_operator(self):
+        expression = self.good_simple_expression.replace('<= 3', '')
+        self._ensure_parse_fails(expression)
+
+    def test_no_dimension_name(self):
+        expression = self.good_simple_expression.replace('hostname', '')
+        self._ensure_parse_fails(expression)
+
+    def test_no_metric_name(self):
+        expression = self.good_simple_expression.replace('cpu.idle_perc', '')
+        self._ensure_parse_fails(expression)
+
+    def test_invalid_period(self):
+        expression = self.good_simple_expression.replace('60', '42')
+        self._ensure_parse_fails(expression)
+
+    def test_zero_period(self):
+        expression = self.good_simple_expression.replace('60', '0')
+        self._ensure_parse_fails(expression)
+
+    def test_negative_period(self):
+        expression = self.good_simple_expression.replace('60', '-60')
+        self._ensure_parse_fails(expression)
+
+    def test_zero_periods(self):
+        expression = self.good_simple_expression.replace('times 4', 'times 0')
+        self._ensure_parse_fails(expression)