Dome A on the Antarctic plateau is likely one of the best observing sites on Earth (Saunders et al. 2009). We used the CSTAR telescope (Yuan et al. 2008) to obtain time-series photometry of 104 stars with i>14.5 mag during 128 days of the 2008 Antarctic winter season (Wang et al. 2011). During the 2010 season we observed 2 × 104 stars with i>15 mag for 183 days (Wang et al. 2012). We detected a total of 262 variables, a 6 × increase relative to previous surveys of the same area and depth carried out from temperate sites (Pojmanski 2004). Our observations show that high-precision, long-term photometry is possible from Antarctica and that astronomically useful data can be obtained during 80% of the winter season.