Ferroelectric polarization related charge conduction have shown intriguing properties of ferroelectric heterostructure devices, such as ferroelectric tunnel junction, switchable diode, and ferroelectric memristor. Recently, ferroelectric heterostructure has been proposed for synapse device exhibiting a high on/off ratio, low power consumption and short process time. In ferroelectric-based synapse devices, gradual electroresistive modulation is associated with change of ferroelectric domain configuration, providing the controllability of the electric conductance for the effective operation of synapse devices. In this work, we demonstrated a ferroelectric-field-effect transistor based synapse devices with channel layer of metal to semiconducting transition (MST) oxide. Ferroelectric polarization switching can modulate the amount of applied energy to MST oxide phase transition and channel conductance at the same time. Our ferroelectric heterostructure with analog-like electroresistive modulation is highly desirable for realizing a efficient synapse device.