Based on the fuzzy theory, the route and process of wiping off appointed noisesfrorn actual signals are discussed, the diagnosis examination methods of identifying thechief influence factors from the measured data sets are studied. Research results showthat because of the non--linear, tolerance--error and self--adaptable of fuzzy system, by u-sing fuzzy method,we can easily and effectively identify and check the main factors pro-ducing and influencing E1 Nino/La Nina, and approximately analyses their influence onand contribution to El Nino/La Nina.