Abstract: In order to investigate the relation between soil moisture and crop biomass, an approach of retrieving regional soil water changes was studied by using remote sensing biomass products of maize in the Junchuan Farm, Northeast of China. The SEBAL model was used as a referenced model to explain the possibility of using the dynamic model of biomass to monitor crop and soil water status. The results showed that the soil water changes of whole growth and development period of maize ranged from -300 mm to -35 mm. The spatial distributions of the retrieved soil water changes and evapotranspiration estimated by using the SEBAL model were similar, and there were little differences between the monitoring results of the two models. These results indicate the dynamic model for retrieving regional soil water changes is a feasible approach for monitoring regional soil water status.