  The Beijing Spectrometer III (BESIII) endcap Time-Of-Filght (ETOF) was
proposed to upgrade with Multigap Resistive Plate Chamber (MRPC) technology to
substitute the current ETOF of scintillator+PMT for extending time resolutin
better than 80 ps and enhance the particle identification capability to satisfy
the higher precision requirement of physics. The ETOF system including MRPC
modules, front end electronics (FEE), CLOCK module, fast control boards and
time to digital modules (TDIG), has been designed, constructed and done some
experimental tests seperately. Aiming at examining the quality of entire ETOF
system and training the operation of all participated parts, a cosmic ray test
system was built at the laboratory and underwent about three months to
guarantee performance. In this paper the results will be presented indicating
that the entire ETOF system works well and satisfies the requirements of the
upgrade.
