  We report the first time-series observations of the short outburst of the
proposed intermediate polar HT Cam (=RX J0757.0+6306). On 2001 December 29, we
detected the object was undergoing a bright outburst at the magnitude of
$m_{vis}=12.2$. Following this detection, we started international joint
observations through VSNET. The light curve showed a gradual decline for the
first 0.5 d. Following this short plateau phase, the rate of decline
dramatically increased to more than 4 mag d$^{-1}$. Within 1.5 d from the
outburst detection, the object almost declined to the quiescent level. During
the rapidly declining phase, long-term modulations with a period of 86 min and
strong pulses with a period of 8.6 min were observed. We concluded that 86 min
and 8.6 min are the orbital period and the spin period of HT Cam, respectively.
By the detection of the spin period, we confirmed the IP classification of HT
Cam. However, its outburst behavior rather resembles that of dwarf novae.
  The discrepancy between the declining rates of the total flux and the pulse
flux strongly suggests that the disk instabilities were taking place during the
outburst.
