Abstract: The role of SSTs in the Indian Ocean (IO) and South China Sea (SCS) in the relationship between the summer precipitation in the Yangtze River valley and the boreal spring Southern Hemisphere annular mode (SAM) was examined by applying regression, composite, correlation and extended singular value decomposition (ESVD). When the boreal spring Southern Hemisphere annular mode index (SAMI) is anomalous, significant SSTA occurs in the middle and high latitudes of South Indian Ocean (SIO) and North Indian Ocean (NIO), which may continue to the summer time and enhance in NIO. Based on the partition in the IO and SCS, the further analyses reveal the extratropical Southern Hemisphere atmospheric circulation anomalies (SAM) in the boreal spring may force SST and induce SSTA in the middle and high latitudes of SIO, which may continue to the summer. The anomalies may propagate from the middle and high latitudes of SIO to NIO (including the Arabian Sea and Bay of Bengal) and SCS and reinforce the SSTA in these regions. The study on relation between East Asian summer monsoon (EASM) and SST indicates that the summer SSTA in NIO according to EASM is similar to that according to the boreal spring SAM, but the signs are opposite. It indicates that the SSTA in the IO and SCS is a bridge between the boreal spring SAM and summer precipitation in the Yangtze River valley. The basic process is that the strong (weak) boreal spring SAM may lead to the high (low) SSTs in the middle and high latitudes in SIO, which propagate to the Arabian Sea, Bay of Bengal and SCS in which the high (low) SSTs conduce to the above (below) than normal summer precipitation in the Yangtze River valley by EASM.