Abstract: The inter-annual variation of the western North Pacific anomalous anticyclone (WNPAC) during El Niño years was investigated based on a variety of air-sea datasets during the period of 1901 to 2000, and its impact on East Asian climate was also discussed. Results show that there are two main spatiotemporal modes for the WNPAC based on empirical orthogonal function (EOF) analysis, i.e., the first mode as its intensity variation and the second mode as its position variation. During the El Niño mature phase in winter, the WNPAC intensity is highly correlated with sea surface temperature anomalies (SSTAs) over the equatorial central-eastern Pacific and the West Pacific (WP) teleconnection pattern at 500 hPa, while its position is highly related to SSTAs over the western North Pacific and Arctic Oscillation (AO). In the subsequent spring season after the El Niño mature phase, the intensity of WNPAC is also highly correlated with SSTAs over the equatorial Atlantic in addition to its high correlation with SSTAs over the equatorial central-eastern Pacific and WP teleconnection pattern in winter, while its position is greatly influenced by SSTAs over the western North Pacific and WP teleconnection pattern. In the subsequent early summer, the intensity of WNPAC is highly related to SSTAs over the northwestern and southwestern Indian Ocean and East Asia-Pacific (EAP) teleconnection pattern. Results further indicate that the inter-annual variations of both the WNPAC intensity and position have great impacts on precipitation over East Asia during El Niño mature winter and subsequent spring and early summer. Additionally, the intensity of the WNPAC is also highly negatively correlated with the occurrence frequency of tropical cyclone over the western North Pacific during the early summer, i.e., the stronger the WNPAC intensity is, the fewer the number of tropical cyclone is, and vice versa.