We propose a scheme for designing the Tsallis distribution regarding the energy probability. Although intensive investigations have been carried out to understand the physical meanings of the three parameters included in the Tsallis distribution, the effect of these parameter values on the physical-state sampling behavior is not yet fully understood. From an invariance property for the distribution, it is found that the independent parameters are two. Constructing two independent local conditions for the energy distribution, we analytically derive the parameter values that obey these conditions. The validity of our scheme was verified from molecular dynamics simulations for a peptide system. (c) 2005 Elsevier B.V. All rights reserved.