Double cyclic variations in orbital period of the eclipsing cataclysmic
  variable EX Dra
  EX Dra is a long-period eclipsing dwarf nova with $\sim2-3$ mag amplitude
outbursts. This star has been monitored photometrically from November, 2009 to
March, 2016 and 29 new mid-eclipse times were obtained. By using new data
together with the published data, the best fit to the $O-C$ curve indicate that
the orbital period of EX Dra have an upward parabolic change while undergoing
double-cyclic variations with the periods of 21.4 and 3.99 years, respectively.
The upward parabolic change reveals a long-term increase at a rate of
$\dot{P}={+7.46}\times10^{-11}{s} {s^{-1}}$. The evolutionary theory of
cataclysmic variables (CVs) predicts that, as a CV evolves, the orbital period
should be decreasing rather than increasing. Secular increase can be explained
as the mass transfer between the secondary and primary or may be just an
observed part of a longer cyclic change. Most plausible explanation for the
double-cyclic variations is a pair of light travel-time effect via the presence
of two companions. Their masses are determined to be
$M_{A}sini'_{A}=29.3(\pm0.6) M_{Jup}$ and $M_{B}sini'_{B}=50.8(\pm0.2)
M_{Jup}$. When the two companions are coplanar to the orbital plane of the
central eclipsing pair, their masses would match to brown dwarfs.
