Longtime in-situ measurements of total ozone from the ground-based Brewer observatories at Longfengshan in Heilongjiang Province and Waliguan in Qinghai Province were analyzed together with the according geopotential height data from NCEP R1 reanalysis series. Abnormal day-to-day fluctuations in the total ozone amount were found at times, which were analyzed in respect to synoptic processes. Results show that the impact of synoptic conditions is highly related to the variation of the total ozone amount. The anomaly in total ozone amount mostly appears in winter and spring (from November to May in the following year). The abnormal high total ozone amounts (the first kind of abnormal data points) always occur when the station is at the rear of the near surface (1000 hPa) cyclone with a simultaneous air pressure trough approaching in lower stratosphere (250 to 70 hPa). The abnormal low total ozone amounts (the second kind of abnormal points) always occur when the station is behind a near surface anticyclone with a simultaneous air pressure ridges approaching in lower stratosphere. The anomaly in total ozone amount can be considered as a signal for the upcoming transition between near surface cyclone and anticyclone.