Abstract:Based on the observation and reanalysis datasets since 1951, the interannual variability of air temperature and precipitation in Shandong under the influence of El Niño/La Niña Southern Oscillation (ENSO) with (accompanied type) or without (isolated type) Indian Ocean Dipole (IOD) are conducted through the composite analysis. It is discovered that there are distinct differences on the effect intensity, extent, phase and spatial pattern of interannual variability between the accompanied and isolated type of ENSO: for the air temperature, with the reinforce of positive IOD(pIOD), El Niño has more notable effect on the air temperature anomalies over the south of Shandong in summer; when El Niño occurs with pIOD, the air temperature in Shandong is higher than normal in autumn, while it is lower when El Niño occurs only, which varies out of phase; when La Niña appears with negative IOD (nIOD), the air temperature over the northwest of Shandong is lower than normal, while it is higher over the east of Shandong Peninsula when La Niña appears only, which varies out of phase too; as a joint influence of La Niña and nIOD, the air temperature over Shandong is higher than normal in autumn; a close correlation exists between the air temperature anomalies at surface and 850 hPa over Shandong during the summer and autumn of El Niño/La Niña. As for the precipitation, under the influence of pIOD, El Niño tends to reduce the precipitation of the north Shandong in summer, but weakens its influence on the negative precipitation anomalies in the middle of Shandong. La Niña occurring with nIOD has a stronger effect on the interannual variability of summer precipitation in Shandong; the precipitation displays significant inhomogenous distribution accompanying with significant positive anomalies in the northwest of Shandong; for the isolated La Niña, the summer precipitation is less than the climatology in the northwest, middle and south of Shandong; the circulation anomalies accompanied with the air temperature anomalies at 850 hPa play a role in the precipitation anomalies over Shandong in summer and autumn.