Using the wavelet power spectrum and composite analysis,the intraseasonal oscillation of 500 hPa zonal winds in spring over the Tibetan Plateau and its relationship to the precipitation in south China is studied,based on the daily NCEP/NCAR reanalysis and the daily precipitation dataset from 753 stations in China.Results reveal that the 10-30 d oscillation is the dominate period of the 500 hPa zonal wind variations over the Tibetan Plateau in spring season,characterized by its eastward propagation in zonal and southward propagation in meridional direction.Results also indicate that this 10-30 d intraseasonal oscillation is closely related to the spring precipitation over the south China.As the low-frequency oscillation over the Tibetan Plateau reaches its peak phase (phase 2-3,i.e.,westerly anomalies over the plateau),there will be positive precipitation anomalies in south China,and vice versa.In addition,the occurrence of the maximum (minimum) precipitation anomalies over south China is about 2 days lagged behind the peak (valley) phase of the intraseasonal oscillation over the plateau.Results further show that the intraseasonal oscillations of 500 hPa zonal wind over the Tibetan Plateau is highly related to an eastward-propagating wave train in the mid-high latitudes and through which the oscillation thus affects spring precipitation over south China.