Аннотация:We have analyzed long-term photometric observations of the dwarf nova EX Dra, a system with a long orbital period, in quiescence, the pre-outburst state, and the active state. The aim of our study was to test the hypothesis of Baptista [2012] that the outbursts in this system are due to an increasing rate of mass outflow from the secondary rather than the thermal instability associated with changing viscosity in the disk.