This paper describes a semantic Association Model called sam ∗ which is designed for modeling not only scientific-statistical databases but also business-oriented databases. The model uses “concepts” and “associations” of these concepts to model the real-world information of a database management environment. Seven general association types are defined and distinguished on the basis of their structural properties, operational characteristics and semantic constraints. They are the basic constructs for an explicit and direct modeling of complex semantic relationships in databases. The model is characterized by 1. (1) its expressive power offered by the seven modeling constructs and the recursive use and nested structuring of these constructs, 2. (2) its recognition of complex data types such as text, ordered set, matrix, time series, vector, set and time as primitive data types which can be directly manipulated by the user using a DML, (3) its support of “principle of relativism” by allowing concepts to be multiply labeled to explicitly specify the conflicting views of these concepts and (4) the distinction it makes between attributes which characterize objects and attributes which statistically summarize a set of objects, together with its support of statistical operations. A network structure and a tabular structure called generalized relation or G-relation are proposed for representing the conceptual and implementation designs of databases respectively. A number of restructuring operations and algebraic operations are also defined for processing G-relations.