A new fuzzy formulation technique based on semitensor product of matrices is proposed in this paper to construct multivariable fuzzy logic systems. A fuzzy relation matrix (FRM) model is suggested for direct modeling and indirect identification of the fuzzy matrix expression using the observed input–output data of fuzzy dynamical process. The center points of fuzzy sets for every output variable are optimized by using least squares estimation. The effectiveness of the proposed fuzzy formulation technology is verified by simulations. Test results show that the proposed formulation technique is an effective design method to construct and optimize fuzzy relation structure matrices for multivariable fuzzy systems. It can be used to design FRM models for multi-input multi-output systems.