Abstract: This paper aims at the relationship between the Indian monsoon and the summer circulation of the East Asia. The diagnostic study reveals a significant correlation between the Indian summer rainfall and the 500 hPa heights over the East Asia, based on NCAR/NCEP reanalysis data sets. The correlation structure seems to be an implicit teleconnection pattern, named as Indian-East-Asian (IEA) pattern, because of no significant correlation between the rainfall and the 500 hPa height above India around. The spatial structure of the IEA pattern implies its important influence on the departures of the 500 hP a height over the East Asia, which exerts impact on the zonal location of the subtropical high in northwestern Pacific while the Pacific-Japan (PJ) pattern affects its meridianal location, as well known. The numerical experiments for acase of 1982 show that the IEA pattern is a key chain that makes the East Asian summer monsoon and South Asian monsoon connected. Notice the tie of the ENSO and Indian monsoon, we introduce two ways by which the ENSO affects the East Asian summer monsoon. They are adirect way: ENSO→PJ Pattern→East Asian summer monsoon, and a selective way: ENSO→south Asian monsoon→IEA pattern→East Asian summer monsoon.