In this paper, by using the method provided in modern physics, the time series data of ENSO evidence are expanded in phase space. The data include: (1) SSTA at 2.5°S, 120°W in the equatorial East pacific during the 1958—1972 period and (2) SOI during the 1949—1983 period. The correlation of the attractors is calculated and the dimension determined, being d_E=3.1 and d_s=3.2 respectively, so that the ENSO events possess strange attractors. As a result, they should be described by at least employing 4 order ordinary differential equations for holding the strange sttractor.