Background: It is imperative to develop new simulation sampling method to characterize IDPs.Stultz et al divided the long sequence IDPs into eight residues long fragments (for α-synuclein, the first two fragments are residues 1-8 and 6-13), then used temperature replica-exchange molecular dynamics (T-REMD) simulation (using implicit solvent model) to construct the structural library of short segments, and then used bayesian statistics to determine a probability distribution for each conformation in the ensemble based on both theoretical and experimental information.