Lake Bosten is the largest inland freshwater lake in China and plays a key role in the local arid-area ecosystem. This study focuses on the dynamics of water salinity of Lake Bosten in the past 55 years (1955-2009) and intends to quantify the associations between the water salinity and the magnitudes of water level, inflow, outflow, total wastewater drainage into the lake, including industrial and residential wastewater. Correlation analysis reveals that the water salinity has strong associations with those six factors (R = -0.810, -0.510, -0.844, 0.903, 0.855, and 0.685, respectively). We predict that water level, inflow and water salinity of Lake Bosten will decline in 2010-2019. This study recommends a reduction in salt input to the Bosten River by reducing industrial wastewater discharge along the river and the development of clean production technology.