Abstract: The characteristics of surface O3 on clesr day,cloudy and rain dya at Waliguan observatory,Lin'an regional station and Longfengshan regional station were analyzed. There were obvious daily variation on clear dya at Lin'an.The maximum(42.9 ppb) and minimum(20.3 ppb) of daily varation presented in autumn and summer, respectively.The daily variation was more regularat Lonfengshan than at Lin'an.The max mum(about 27 ppb)presented in autumn at Lonfengshan.There was not obvious daily variation and also daily range was smallerin other seasons except summer(there were weak daily variation)at Wailiguan.Butthe surface O3 concentration in summer was higher than winter.The surface O3 concentration on clear day of summerat Waliguan was over 20 ppb higher than itat Longfengshan and Linan.Except daily variation was not very regularand daily range was smalleron overcastat Linan and Longfengshan,the others ere same to on clear day.There was non-daily variation. also daily range is smalleston overcastat Waliguan.Butthe surface O3 concentration in summer was still higher than winter.Both golbal radiation adn NOx concentration were main factors to control surface O3 concentration on clear day and overcastat Longfengshan and Lin'an.They broutht into important play in different seasons and areas.The main reason for higherair pollutant concentration in summerat Waliguan was that airflow of higher air pollutant concentration of area around Qinghai-Tibetan plateau transported into this area.The similar effect of transportation was obtained at Mauna Loa observatory.The distribution characteristics of surface O3 concentration increasing with vertical high in tro posphere decided the difference of surface O3 between east and west in China.