  We carried out time-resolved $V$-band photometry of DM Lyr during long
outbursts in 1996 July and in 1996 February-March at Ouda Station, Kyoto
University and at Osaka Kyoiku University. Since superhumps were clearly
detected in the light curves, DM Lyr was first identified with an SU UMa-type
dwarf nova. The superhump period is 0.0673(2) d, and the superhump excess is
2.8(3) %. The duration of the superoutburst, the outburst amplitude, the
decline rate in the plateau phase, and the superhump excess were typical values
for a usual SU UMa star. According to visual and CCD observations reported to
VSNET, this star has experienced a dramatic change of the outburst pattern from
a superoutburst phase to a normal outburst phase. There may exist mechanisms to
decrease the number of the normal outburst between two successive
superoutbursts and to elongate the recurrence cycle of the superoutburst.
