Abstract: An algorithm is presented for the improvement of harmonic tidal analysis along T/P tracks,in which the differences between the observed sea surface heights at adjacent points are taken as observations,and the observation equations are constrained with the results of the cross over analysis.It is indicated that the algorithm presented can efficiently remove non-tidal effects in the altimeter observations,and improve the precision of tide parameters.Moreover,parameters along altimetry tracks represent smoother distribution than those obtained from traditional algorithms.