The whole India summer rainfall data set from the Indian Institute of Tropical Meteorology,monthly Reanalysis data set from European Center for Medium-Range Weather Forecasts(ECMWF),Japan Meteorological Agency/Japan(JRA-55) and National Center for Environment Prediction/National Center for Atmospheric Research(NCEP/NCAR) during 1958—2014 are used to study the relations between Somali jet and Indian summer rainfall.It is found that before 1983,SMJ had significant positive correlation with the Indian summer rainfall,which accorded with our past understanding.But after 1983,the positive correlation has significantly weakened.Further study indicated that before 1983,there was a positive anomaly of the Somali equatorial airflow in the South India ocean and the Somali coast and there was a positive anomalous southwest wind in the Arabia sea and the northwest of India,which increased the summer water vapor transport to India and further strengthened Indian summer precipitation.SMJ was closely related to the South Asia high.However,after 1983,the south-west wind positive anomaly in the north of the Arabia sea and the northwest of India has weakened,particularly in the west coast of India.The correlation between SMJ and the South Asia high has also weakened,which results in the weakening correlation between SMJ and Indian summer rainfall.In addition,while the relations between Indian summer rainfall and ENSO,SMJ are weakening,it is preliminarily shown that the correlation between Indian summer rainfall and East Asia/Pacific Teleconnection (EAP) is significantly strengthening.