I am not sure what you want to achieve with "from child model I want to access all the property of parent model". In Alfresco model definition, you can import none or many existing model namespaces in order to reference elements, e.g. to create child types, create associations (peer / parent-child), reuse constraints, set default aspects, or override inherited property definitions (as far as Alfresco supports overriding). With regards to parent-child, if you import another model, you only ever defined parent-child associations where a type/aspect of the imported model is used as the child element - it is technically not possible to create a (child) model which references the (parent) model to create an association where a type of the (child) model is used as the child of an association.
