Database design methodologies should facilitate database modeling, effectively support database processing, and transform a conceptual schema of the database to a high-performance database schema in the model of the corresponding DBMS. The Entity-Relationship Model is extended to theHigher-orderEntity-RelationshipModel (HERM) which can be used as a high-level, simple and comprehensive database design model for the complete database information on the structure, operations, static and dynamic semantics. The model has the expressive power of semantic models and possesses the simplicity of the entity-relationship model. The paper shows that the model has a well-founded semantics. Several semantical constraints are considered for this model.