Dome A on the Antarctica plateau is likely one of the best observing sites on earth thanks for the excellent atmospheric conditions.We detected 157 variable stars using one of the CSTAR telescopes during 128 days of the 2008 Antarctic winter.Based on 183 days observations of the 2010 Antarctic winter we recovered 155 of the 157 variable stars discovered during the 2008 observing season and discovered an additional 107 variables thanks to broader synoptic coverage, a deeper magnitude limit and a larger field of view relative to our previous observations.We used the photometric data set to derive site statistics from Dome A.Based on two years of observations, we find that extinction due to clouds is less than 0.1 and 0.4 mag during 45% and 75% of the dark time, respectively.