The paper discusses theoretical foundations of a formal description of monitoring and control systems (MTSs) that are used for the monitoring and control of various natural and technological systems (NTSs). The performed state-of-theart analysis has demonstrated that the theory, methods and techniques related to the application of various types of models, such as mathematical, logical-algebraic, logical-linguistic, simulation and combined ones, for describing NTO MCS are widely used. On that basis, a conceptual description of NTO monitoring and control systems is proposed. It is based on a concept of NTO MCS multi-model description. The proposed general model includes particular dynamic models that describe motion control, channel control, operation control, flow control, resource control, operation parameter control, structure dynamic control, and auxiliary operation control of the considered monitoring and control system. The proposed interpretation of NTO MCS structure dynamics control processes provides advantages of applying the modern optimal control theory to NTO MCS analysis and synthesis.