Base on the cross wavelet and wavelet coherence transform methods,by using the daily averaged data derived from the NCEP/NCAR reanalysis dataset and interpolated outgoing long wave radiation(OLR) data provided by the National Oceanic and Atmospheric Administration(NOAA),the abnormal activities of the West Pacific subtropical high during the summer of 2006 and its time-delayed phase characteristics with the East Asian summer monsoon system are analyzed.The results show that the cross wavelet and wavelet coherence spectrum of the subtropical high index and the characteristic indices of East Asian summon monsoon system members can reveal the time-frequency characteristics and delayed correlation between those different factors and the subtropical high index on 14—20 days time-scale.The Mascarene high and South Asia high may predict the westward extension and northward advance of the subtropical high better;the strengthening and northward movement of ITCZ and the subtropical jet stream are synchronized with the northward jump of the subtropical high ridge;the northward advance of the subtropical high favors precipitation in Southern China,in turn,the formation of rainfall belt benefits the further westward extension of the subtropical high.