The field-controlled phase transition is a promising concept for the design of novel multiferroic materials. Rare-earth samarium-modified bismuth ferrite (Bi1-xSmxFeO3) possesses a morphotropic phase boundary (MPB) that has similar free energies between the polar and nonpolar phases, making it an exceptional candidate. In this study, we investigated the electric field cycling-dependent behavior of ferroelectricity in Bi1-xSmxFeO3 ceramics near MPB. During electric field cycling, a significantly enhanced remanent polarization was observed. Cycled Bi0.86Sm0.14FeO3 and Bi0.84Sm0.16FeO3 exhibited enhanced ferroelectric (remanent polarization >30 mu C/cm(2)) and magnetic (remanent magnetization >0.20 emu/g) properties at room temperature. Through a systematic study of dynamic hysteresis measurements and a structural analysis, these results were attributed to a field cycling-induced nonpolar-to-polar phase transition. In situ high temperature measurements showed a previously unreported sharp anomaly of the piezoelectric coefficient (d(33)) near the magnetic transition point (T-N). These results indicated a strong magnetoelectric coupling in rare earth-modified bismuth ferrite materials, suggesting the possibility of magnetically modulated piezoelectricity.