The relation between summer south and north branch rainbands over the Changjiang River basin and spring Pacific sea surface temperature (SST) is numerically investigated using the NCAR/CAM 3.0 global atmospheric circulation model.The results show that spring (MAM) SST anomaly in the eastern equatorial Pacific (EEP;5°S-5°N,150-90°W) has important impact on summer (JJA) precipitation over the two branch rainbands:when spring SST anomaly in the EEP is positive,summer rainfall of south branch rainband is deficit,and that of north branch raindand is not obvious affected;and when the spring SST anomaly is negative,summer rainfall of south branch rainband is excessive,and that of north branch rainband is deficit.Anomalous spring SST forcing can trigger teleconnection wavetrains in the troposphere of Northern Hemisphere,which affect summer precipitation of both south and north branch rainbands in the Changjiang River basin,but with more obvious influence on the precipitation of the former.