Abstract: The impact of air－sea coupling over the Indian Ocean on the climatological state of tropical atmospheric circulation in boreal summer is investigated by diagnosing the long－term simulations from the high－resolution SINTEX－F (Scale INTeraction EXperiment－FRCGC) coupled ocean－atmosphere model. The main conclusions are listed as below.(1) Air－sea interactions over the tropical Indian Ocean strengthen easterlies over the tropical eastern Indian Ocean, and induce cyclonic shearing circulation over the north of western and central Pacific.(2) The impact of air－sea interactions on the climatological mean state over the Indian Ocean is primarily attributed to the asymmetric atmospheric response to positive and negative Indian Ocean dipole modes and the asymmetric response to positive and negative basin－wide modes over the tropical Indian Ocean.(3) Air－sea interactions on both interannual and intraseasonal timescales contribute to the change of the climatological mean state over the Indian Ocean; they account for 60% (interannual timescale) and 40% (intraseasonal timescale) respectively. While the impact of the intraseasonal air－sea interaction on the mean circulation is more important in the equatorial Pacific region, the impact of the interannual air－sea interaction is more important in the off－equatorial Pacific region. The impact of air－sea interactions on both the timescales exhibits a significant interannual variation and amplitude asymmetry between the positive and negative anomalies.