Using the dipole mode index(DMI), Nino3 index, and five East Asian summer monsoon(EASM) indices, the interdecadal variations of interannual relationships of East Asian summer monsoon(EASM) with Indian Ocean dipole(IOD) and ENSO are examined, respectively, in the present paper. There is appreciable positive correlation between EASM and IOD in the most of time-periods except the 1980s and the beginning of the 1990s. IOD and ENSO have opposite effects on EASM. When the correlation between IOD and EASM is strongly positive, the ENSO-EASM correlation is weaker. However, when the IOD-EASM correlation weakens in the end of the 1970s and early 1980s, the ENSO-EASM correlation is noticeable. The obvious difference of sea surface temperatures between the period of 1972-1982 and that of 1983-1993, may result in changes of the period and pattern of circulation in the air-sea interaction process, thus leading to the interdecadal variations of relationships of East Asian summer monsoon with IOD and ENSO.