The rate of obsolescence of knowledge in the field of technology is very rapid these days. However, certain basic principles and methods of analysis remain the sallle even amidst swift technological changes. The subject mailer of linear systems is one such example. Methods for the analysis and design of state variable systems are growing rapidly. These developments are motivated by extensive applications, in particular, to such areas as mechatronic systems, robotics, aircraft flight control and any other technological systems. A number of innovative ideas, results, and approaches have appeared in this area during the past few decades. State space representation, The concept of state, Block Diagram for State Space, Decomposition, Canonical form, Solution of State Equation, Transfer Matrix, Controllability, Observability, State Transition Matrix, State Equation Based Modeling, State Variables for Electrical Networks, State Variable Modelling of Physical Systems, SISO, SIMO, MISO, MIMO, Duality Principle, Cayley - Hamilton Technique etc. This book mainly for Engineering Students, Competitive Exams, Research Purposes etc.