required=True,
                             help=_('YAML template or CSAR file to parse.'))
 
+        parser.add_argument('-nrpv', dest='no_required_paras_valid',
+                            action='store_true', default=False,
+                            help=_('Ignore input parameter validation '
+                                   'when parse template.'))
+
         return parser
 
     def main(self, argv):
         parser = self.get_parser(argv)
         (args, extra_args) = parser.parse_known_args(argv)
         path = args.template_file
+        nrpv = args.no_required_paras_valid
         if os.path.isfile(path):
-            self.parse(path)
+            self.parse(path, no_required_paras_valid=nrpv)
         elif toscaparser.utils.urlutils.UrlUtils.validate_url(path):
-            self.parse(path, False)
+            self.parse(path, False, no_required_paras_valid=nrpv)
         else:
             raise ValueError(_('"%(path)s" is not a valid file.')
                              % {'path': path})
 
-    def parse(self, path, a_file=True):
+    def parse(self, path, a_file=True, no_required_paras_valid=False):
         output = None
-        tosca = ToscaTemplate(path, None, a_file)
+        tosca = ToscaTemplate(path, None, a_file,
+                              no_required_paras_valid=no_required_paras_valid)
 
         version = tosca.version
         if tosca.version:
 
 from toscaparser.common.exception import ExceptionCollector
 from toscaparser.common.exception import InvalidTemplateVersion
 from toscaparser.common.exception import MissingRequiredFieldError
+from toscaparser.common.exception import MissingRequiredParameterError
 from toscaparser.common.exception import UnknownFieldError
 from toscaparser.common.exception import ValidationError
 from toscaparser.elements.entity_type import update_definitions
 
     '''Load the template data.'''
     def __init__(self, path=None, parsed_params=None, a_file=True,
-                 yaml_dict_tpl=None, sub_mapped_node_template=None):
+                 yaml_dict_tpl=None, sub_mapped_node_template=None,
+                 no_required_paras_valid=False):
         if sub_mapped_node_template is None:
             ExceptionCollector.start()
         self.a_file = a_file
         self.sub_mapped_node_template = sub_mapped_node_template
         self.nested_tosca_tpls_with_topology = {}
         self.nested_tosca_templates_with_topology = []
+        self.no_required_paras_valid = no_required_paras_valid
         if path:
             self.input_path = path
             self.path = self._get_path(path)
                     nested_template = ToscaTemplate(
                         path=fname, parsed_params=parsed_params,
                         yaml_dict_tpl=tosca_tpl,
-                        sub_mapped_node_template=nodetemplate)
+                        sub_mapped_node_template=nodetemplate,
+                        no_required_paras_valid=self.no_required_paras_valid)
                     if nested_template._has_substitution_mappings():
                         # Record the nested templates in top level template
                         self.nested_tosca_templates_with_topology.\
 
     def verify_template(self):
         if ExceptionCollector.exceptionsCaught():
+            if self.no_required_paras_valid:
+                ExceptionCollector.removeException(
+                    MissingRequiredParameterError)
+
             if self.input_path:
                 raise ValidationError(
                     message=(_('\nThe input "%(path)s" failed validation with '