A two-layer tropical Pacific ocean model and the FSU pseudo windstress are employed to investigate the response of the model ocean to the anomalous windstress on different time scales.The timeseries of windstress is decomposed into an ENSO-time-scale component and the residual part,by use of a band-pass filter.It is found that the ENSO cycles are successfully generated with the forcing of windstress anomalies on ENSO time scale.The SSTA has almost the same period and phase as compared to those simulated with the forcing of the total windstress although the anomalous windstress on ENSO time scale only explains 30% of total variance of total windstress anomalies.The rest part that explains approximately 60% of total variance of windstress anomalies drives ocean to produce a variation with much smaller amplitude in sea surface temperature.The Kelvin waves can be excited in the first layer of the model-ocean by both the ENSO time scale wind-stress component and the residual part (non-ENSO) on other time-scales.A theoretical explanation is given as the reason why the intensities of sea surface temperature anomalies are much different although the intensities of Kelvin modes in the two experiments are very comparable.