We report on V and R high speed photometry of the dwarf nova EX Dra in quiescence and in outburst .
The analysis of the outburst lightcurves indicates that the outbursts do not start in the outer disc regions .
The disc expands during the rise to maximum and shrinks during decline and along the following quiescent period .
The decrease in brightness at the later stages of the outburst is due to the fading of the light from the inner disc regions .
At the end of two outbursts the system was seen to go through a phase of lower brightness , characterized by an out-of-eclipse level \simeq 15 per cent lower than the typical quiescent level and by the fairly symmetric eclipse of a compact source at disc centre with little evidence of a bright spot at disc rim .

New eclipse timings were measured from the lightcurves taken in quiescence and a revised ephemeris was derived .
The residuals with respect to the linear ephemeris are well described by a sinusoid of amplitude 1.2 minutes and period \simeq 4 years and are possibly related to a solar-like magnetic activity cycle in the secondary star .
Eclipse phases of the compact central source and of the bright spot were used to derive the geometry of the binary .
By constraining the gas stream trajectory to pass through the observed position of the bright spot we find q = 0.72 \pm 0.06 and i = 85 ^ { +3 } _ { -2 } degrees .
The binary parameters were estimated by combining the measured mass ratio with the assumption that the secondary star obeys an empirical main sequence mass-radius relation .
We find M _ { 1 } = 0.75 \pm 0.15 M _ { \odot } and M _ { 2 } = 0.54 \pm 0.10 M _ { \odot } .
The results indicate that the white dwarf at disc centre is surrounded by an extended and variable atmosphere or boundary layer of at least 3 times its radius and a temperature of T \simeq 28000 K .
The fluxes at mid-eclipse yield an upper limit to the contribution of the secondary star and lead to a lower limit photometric parallax distance of D = 290 \pm 80 pc .
The fluxes of the secondary star are well matched by those of a M 0 \pm 2 main sequence star .