Decentralized control is a well established approach to the control of multivariable plants. In this approach, control structure design and in particular input-output pairing is a vital stage in the design procedure. There are several methods such as RGA, Balanced-Realization, Hankel-norm based and gramian based approach to select the appropriate input/output pairs in linear multivariable plants. In this paper, a new input-output pairing method for stable multivariable plants is proposed. This new approach is based upon the cross-gramian matrix of SISO elementary subsystems built from the original MIMO plant. The main advantages of the method are simplicity and proposing an overall measure to choose the best input output pairs.