Reverse-impact experiments are performed on bismuth (Bi) to probe into the release melting from shock pressures in a pressure range of 11-16 GPa. A displacement interferometer system for any reflector (DISAR) is employed to measure the particle velocity history at the impact interface of LiF window with Bi flyer. The obtained experimental data, together with the results from characteristic formulations and one-dimensional hydrodynamic simulations, indicate that bismuth is converted into the body-center-cubic phase under shock loading, and then melted with the releasing of state from the initial shock (Hugoniot). The inflexion on the release wave profiles is attributed to the release melting. The proposed method and extracted results are of importance for developing the phase-change diagnostics and understanding phase-transition behavior of Bi and its analogues.