An end-cap Time-of-Flight (E-TOF) system with higher granularity compare to the current E-TOF and intrinsic time resolution of better than 50 ps will extend the K/pi separation (2 sigma) momentum range to 1.4 GeV/c and enhance the physics capability of Beijing Spectrometer (BESIII). A R&D project was carried out aiming at upgrading the current BESIII E-TOF with the Multi-gap Resistive Plate Chamber (MRPC). The beam test for the MRPC prototype, together with the custom-designed Front End Electronics (FEE) and TDC boards, was performed at the BEPC E3 line in the last years. The test results show that the detector has stable performance at different positions and working High Voltage (HV). A time resolution of better than 50 ps can be achieved. The different performance between pion and proton events is also discussed.