In order to reveal the characteristics of the boundary layer ozone vertical profiles in winter in Urumqi, the observation experiment with tethered balloon has been carried out from 11 to 13 January 2008. Based on the observation experiment data and some related data， the vertical distribution characters of ozone concentration and the relationship with meteorological factors were studied. The results showed that: The ozone concentration is lower below 500-800 m during the daytime and the distribution area of high concentration ozone appears over this height. However, the ozone concentration is lower in the range of whole observed height at night. There existed a close relationship between the ozone concentration and the meteorological factors including solar radiation， temperature stratification， wind and relative humidity.The distribution area of high concentration ozone exsits over the inversion base， and there is a significant inverse correlation between the ozone concentration and the relative humidity. The nitrogen oxides in the near surface has an important influence on ozone concentration. The above facts obtained indicate that the ozone in the lower troposphere has significant temporal and spatial variations in winter in Urumqi， which results from the joint effects of various factors.