  EM Cygni is a Z Cam-subtype eclipsing dwarf nova. Its orbital period
variations were reported in the past but the results were in conflict to each
other while other studies allowed the possibility of no period variation. In
this study we report accurate new times of minima of this eclipsing binary and
update its O-C diagram. We also estimate the mass transfer rate in EM Cygni
system and conclude that the mass transfer is far from the critical value. The
mass transfer rate determined from the eclipse timings is in agreement with the
spectroscopically determined value.
