Description: The Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) missions have been recording Earth's time-variable gravity for nearly 20 years. The resulting gravity data has been used to study mass changes and to invert global terrestrial water storage change (TWSC). This study derives a new method for producing global TWSC maps in the form of so-called “mass concentration (mascon)”. In this study, we show that the use of irregularly shaped mascon patches that follow land/ocean boundaries reduces the leakage of land signals into ocean regions and vice versa. One highlight of this study is that we divided the global mascon patches according to basin boundaries as with land/ocean boundaries. The advantage of this divided method is that it is clearer and more reliable to statistic the basin’s TWSC and avoiding cross-basin contamination. On the basis of dividing mascon patches by basins, we select 20 global largest river basins and statistically analyze the time series, trend and amplitude of TWSC signals, compared with different research groups—JPL, CSR and GSFC. The results show that the spatial distribution of TWSC in some basins by this mascon solution is more reasonable than other research groups (JPL, CSR, GSFC), which avoids mutual leakage and interaction of mass changes between basins. From the time series of TWSC in statistical 20 basins, this mascon solution can capture higher amplitude and obtain more true signals, which brings an improvement in hydrological signal recovery compared to the other mascon solutions.