Using the monthly precipitation data of 160 stations in China, Hadley Center sea surface temperature (SST) data, NOAA outgoing longwave radiation (OLR) data and NCEP/NCAR reanalysis data from 1979-2019, the impact of the summer tropical Atlantic sea temperature (TAST) on the first rainy season precipitation in South China (FRSP) is investigated. Base on the correlation analysis and information flow theory, the results show that the increase (decrease) of previous summer TAST partly leads to the decrease (increase) of FRSP. The SST rising in the key region (35°W-10°E, 10°S-5°N) can enhance the Walker circulation and induces an anomalous subsidence over the Pacific, which lead to an easterly wind anomaly over the central and western equatorial Pacific in summer. The ocean-atmosphere interactions promoted the development of La Ni?a in the following autumn and winter. The same mechanisms act for the negative SST anomaly but with opposite sign, and conducive to the development of El Ni?o. When the La Ni?a（El Ni?o）reach its peak in winner, the convection heating intensify (suppressed) in the western Pacific which triggered abnormal cyclones (anticyclones) response in the lower troposphere to its north. The anomalies persist until the first rainy season in second year, causing the abnormal cyclones (anticyclones) maintained which, on the one hand, is conducive to the weakening and eastward retreat (strengthening its westward extension) of the Western Pacific Subtropical High (WPSH), thus reducing (increasing) the transport of water vapor from the South China Sea to South China. On the other hand, the convective activity (suppression) in tropical areas is conducive to strengthening (weakening) the local Hadley circulation, resulting in the subsidence (ascent) anomaly in South China, and suppressing (intensifying) the convection. In addition, the negative (positive) SST anomaly in the eastern Pacific excited a Pacific-North American (PNA) like wave train, and the SST anomalies in the North Atlantic further activates the Eurasian (EU) wave train that making the Eurasian mid-high latitudes region shows negative (positive)-positive (negative)-negative (positive) geopotential height anomalies, which is unfavorable (favorable) for the cold air affecting South China, and eventually cause FRSP negative (positive) anomalies.