Based on the sub-project "Interaction between tropical Indian Ocean circulation dynamics and monsoon and its effect" of the Strategic Priority Research Program of the Chinese Academy of Sciences "Pan-Third Pole environment change study for green Silk Road development",this paper summarizes research progresses on the upper tropical Indian Ocean circulations,the effect of salinity variability on the classical air-sea coupled processes in the Indian Ocean,and the climatic influence of air-sea interaction in the Indian Ocean on the moisture transport over the Pan-Third Pole.Three key scientific issues are then emphasized as follow:three-dimensional linkage mechanism of the upper Indian Ocean circulation variability,response and feedback mechanism of air-sea interactions to the basin-scale thermohaline redistribution in the Indian Ocean,and influence mechanism of Indian Ocean air-sea coupled modes on the climate change over the Pan-Third Pole.Finally,the ultimate objective of this sub-project are also stated,which are:to overall understand the upper ocean circulation systems in the tropical Indian Ocean and advance the understanding of the influence of air-sea interaction in the Indian Ocean on the moisture transport over the Pan-Third Pole;to improve the prediction skill of the Pan-Third Pole climate and promote the security ability of Indian Ocean expedition and channel monitor on the maritime Silk Road;and finally to serve the Belt and Road Initiative.