[Objective] The objective of the study is to monitor the spatio-temporal evolution of saline soil in Songnen Plain and provide a theoretical basis for the prevention and treatment of saline soil in this region. [Methods] We established a regression model based on MODIS images and the field measured samples to retrieve soil salt content on Songnen Plain quantitatively. Study period can be divided into three sub-periods: period one(2000—2004), period two(2004—2008) and period three(2008—2013). [Results] The area of saline-alkali land increased and salinization was becoming worse in period one and two, and the rate of increase reached 5 109.75 km²/a and 2 240.62 km²/a respectively. After the turning point in 2008, the area of saline-alkali land(mainly the light saline-alkali land) decreased in period three, but the salinization degree was still growing. [Conclusion] Songnen Plain salinization is not optimistic, we should take emergent measures to prevent the further salinization and to ensure the healthy development of eco-environment of Songnen Plain.