Abstract: Lamb-Jenkinson atmospheric circulation classification scheme was used to classify the circulation type of daily average sea level pressure over Beijing in 1948-2008. The following conclusions are drawn that among 27 circulation types, primary types are A, C and SW, and their occurrence frequencies are 23.8%, 15.4% and 7.0%, respectively. Frequencies of types A and C tend to increase, but the increasing rate of type A is much greater than that of type C. The seasonal primary circulation types are A and C in spring, C and SW in summer, and A in autumn and winter, but type CSW can not be ignored in summer. It is fine and cool in winter Beijing under type A, mostly rainy in summer under type C and rainless under type SW, and dry and hot under type CSW, especially after 2000.

Key words: Beijing, atmospheric circulation type, Lamb-Jenkinson circulation classification, climatological characteristics