Abstract: The saline- alkali land development mode of“Shang Mian Xia Yu”or“Shang Liang Xia Yu”started 20 years ago. In recent years, with the improvement of shrimp cultivation, the mode has a rapid development in the Boxing Region of Shandong Province. Investigating the improvement effects on salinealkali land with the mode of“Shang Mian Xia Yu”could provide a theoretical basis for further wide promotion of this mode. In Boxing County, 3 sample points were chosen, including saline- alkali land without development, raised fields soil improved through“Shang Mian Xia Yu”mode for 2 years and 20 years later. In order to reduce the influence of sample points’soil quality on the test results, 3 sample points were within 10 km distance. Each sample point was sampled in 5 soil layers, respectively, 0-20, 20-40, 40-60, 60-80, 80- 100 cm soil layer. The salinity, alkalinity, pH value, quantity of organic matter and the amount of culturable microorganisms of the three different soil sample points were studied. The results showed that after 2 years of improvement, the desalination rate reached 59.7%, after 20 years improvement, the desalination rate reached 90.3%. The soil alkalinity did not change significantly after 2 years of improvement, however, soil alkalinity decreased from 2.004×10-3 mol/L to 0.6311×10-3 mol/L after 20 years of improvement, which showed that the soil alkalinity in saline- alkali land was more difficult to improve than soil salinity. With the increase of improving years, each soil layer’s pH value was gradually reduced compared with that of the saline-alkali land without development and almost close to neutral. The soil organic matter content was enhanced by 15.58% after 20 years of improvement. The amount of cultivable microorganisms in 0-20 cm soil was 12.73 times of that in the saline-alkali land without development after 2 years of improvements. Overall,“Shang Mian Xia Yu”has a good improvement effect on the saline-alkali soil along the Yellow River and this mode is an effective saline-alkali land improvement measure that deserves extending.