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Based on the observed data from the Yongxing Island weather station in Xisha Islands of the South China Sea and the NCEP/NCAR reanalysis datasets from 1960 to 2012, the characteristics of summer climate change in Xisha are analyzed, and relationships with the sealevel pressure in spring and summer in the Antarctic are discussed. The results show that there was a continuous decline of precipitation and increasing of temperature as well as remarkable weakening of wind velocity during 1960-2012 in Xisha, and meanwhile, there existed apparent interannual variability of the quasitwoyear and the decadal variability of 7 to 11 years. The results of regression analysis and correlation analysis demonstrate that the summer precipitation in Xisha was more than normal, the temperature is lower than normal, the wind velocity is more strong than normal when the sea level pressure in boreal summer and spring over the Antarctic is significantly higher than normal, resembling the negative phase of Antarctic Oscillation (AAO), and vice versa. The positive phase of AAO in spring and summer, on the one hand, resulted in the weak East summer monsoon at the interdecadal scale and led to the weak India monsoon at the interannual scale, on the other hand, inducing the decrease of precipitation and increase of temperature as well as the weakness of wind velocity in summer in Xisha.