Using 1961一2000 dekadly precipitation from 76 weather stations in the Qinling mountains and the surroundings and largescale grid winds at 850 hPa from NCAR/ NCEP ,the climatology spatial一temporal characteristics of the precipitation and their as sociations with the atmospheric circulation have been analyzed in this paper. The results show that the flood season for the 40一year average occurs in the period from the third dekad of June to the first dekad of October ,during which there are two peaks of precipitation ahe first dekad of July and the first dekad of September. The rainfall in the south side of the Qinling mountains is obviously higher than that in the north side ,although the interannual variations of both are basically consistent. The Qinling mountains and the surroundings are mainly controlled by the southwesterly monsson in the flood season ,e}ecially in the midsummer ,but are mainly impacted by the southeasterly monsoon in the early autumn. The composite analyses show that when theprecipitation is more(less)than normal ,the southerly wind at the south boundary of the study area is often stronger(weaker) than normal in the flood season. By the regression analyses ,it is found that the increased rainfall in a dekad in the flood season generally corresponds to the strengthened Somali
Jet and southwesterly monsoon in the dekad with a two一dekad lead ,and an anomaly anticyclone near Taiwan in the one一dekadlead
dekad and the same dekad.