The climatological monthly mean sea surface height (SSH) anomalies derived from T/P altimeter in the northern Indian Ocean, during 1993 to 1997, are used to prepare time-longitude plots. Along the equator they reveal strong semi-annual variability of sea level anomaly. The plots along 6 degrees, 12 degrees and 18 degrees N show the westward propagating (Rossby waves) features, the speed of which decreases from 7.74 cm s super(-1) at 12 degrees N to 4.50 cm s super(-1) at 18 degrees N. These speeds are comparable to the theoretical phase speeds of Rossby waves. Time-longitude plots of zonal wind stress, obtained from the FSU wind stress climatology for the same period as that of T/P data, shows that the eastward propagation in the sea level field in the equatorial region is driven by zonal wind stress variability, where as the westward propagation in the higher latitudes is found to have little influence with the zonal wind stress variability. Moreover, it is found that the westward propagation of high (low) sea level anomaly along 12 degrees N in the Arabian Sea appears to be driven by the Ekman convergence (divergence) associated with the negative (positive) wind-stress curl near the southern tip of the peninsular India and Sri Lanka between 5 and 10 degrees N.