Modal strain energy (MSE) is of primary importance for its extensive applications in many fields of engineering [3], [4]. The element MSE sensitivity with respect to changes in the physical parameters is derived based on an algebraic method by Yan and Ren [2]. The subject paper by Li et al. [1] proposes an interesting idea termed as variational principle for calculating the sensitivity of the element MSE. This method is certainly interesting and it provides a new approach for sensitivity analysis of MSE. This discussion intends to clarify several critical issues associated with the paper.