Global mean sea level(GMSL) has not only significant secular trend and seasonal variations,but also inter-annual and decadal variations.This paper reconstructs the time series of GMSL variations between 1948 and 2007 by combining satellite altimeter measurements and tide gauge observations.Based on the time series,the acceleration of GMSL rise in the second half of 20th century is estimated to be 0.010±0.009 mm/a 2,and multi-scale low frequency sea level oscillations including decadal variations are detected,and the high-rate of GMSL rise during 1993-2003 is locate in the ascending phase of low frequency oscillation.Then,using the reconstructed GMSL time series after removing the secular trend from satellite altimetry and tide gauges measurements,it shows that low frequency signal of sea level variation has strong correlations with the index of El Ni o/Southern Oscillation(ENSO) and Pacific Decadal Oscillation(PDO).But in several time periods,they have large difference due to effects of both high frequency occurrence of El Ni o and La Ni a phenomenon and short term switch of PDO events. Global mean sea level (GMSL) has not only significant secular trend and seasonal variations, but also inter-annual and decadal variations. This paper reconstructs the time series of GMSL variations between 1948 and 2007 by combining satellite altimeter measurements and tide gauge observations. on the time series, the acceleration of GMSL rise in the second half of 20th century is estimated to be 0.010 ± 0.009 mm / a 2, and multi-scale low frequency sea level oscillations including decadal variations are detected, and the high-rate of GMSL rise during 1993-2003 is locate in the ascending phase of low frequency oscillation. Chen, using the reconstructed GMSL time series after removing the secular trend from satellite altimetry and tide gauges measurements, it shows that low frequency signal of sea level variation has strong correlations with the index of El Ni o / Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) .But in several time periods, they have large difference due to effects of both high frequency occurrence of El Ni o and La Ni a phenomenon and short term switch of PDO events.