The time-frequency structure of sea surface temperature anomaly (SSTA) in the Nino regions was studied with wavelet transform techniques using SST data from 1950 to 2003 over the Nino regions. The results show that there were multi-scaled structures nested one another in SSTA with varied scales of 2-7, 8-20 and over 30 years. The power of the warm/cold events was concentrated on the 2-7 year scales with the quasi-four year fluctuation being the most remarkable. The power and frequency structure of the same event are different in different Nino regions. The intensity of oscillations is increasing at all scales after 1970 and shows a tendency towards low frequencies.