The characteristic low-frequency oscillation of the sea surface temperature anomaly (SSTA) of ENSO related regions, Niño 1+2, Niño 3, Niño 4 and Niño West, and the Southern Oscillation index (SOI) is analyzed with the method of maximum entropy spectrum.Antarctic sea ice is divided into 4 regions, i.e.East Antarctic is Region Ⅰ (0°-120°E), the region dominated by Ross Sea ice is Region Ⅱ (120°E-120°W), the region dominated by Ross Sea ice is Region Ⅲ (120°W-0°), and the whole Antarctic sea ice area is Region Ⅳ.Also, the month-to-month correlation series of the sea ice with ENSO from contemporary to 5-years lag is calculated.The optimum correlation period is selected from the series.The characteristics and the rules obtained are as follows. 1.There are a common 4-years main period of the SSTA of Niños 1+2, 3 and 4, a rather strong 4-years secondary period and a quasi-8-years main period of that of Niño West.