Abstract: The problem of synthesis of the decentralized control structure in continuous industrial processes is addressed in this paper. Firstly, the feasibility of general decentralized control structure (GDCS) is discussed. The necessary and sufficient conditions will be given. It is shown that under these conditions, there exists a corresponding decentralized robust controller that ensures the asymptotic stability of the resulting closed-loop system. Secondly, the problem of finding the simplest feasible GDCS is also studied. A relevant synthesizing algorithm in order to find minimal measurement variables, minimal control variables, and the simplest feedback structure is given. The synthesis algorithm has been successfully applied to the control system design and synthesis for a reactor-regenerator system in a fluidized catalytic cracking unit.