[Objective] The objective of the study is to analyze the spatial-temporal changes of water transparency and related influencing factors in Wuliangsu Lake, Inner Mongolia and to provide theoretical basis and technical support for submerged plants recovery and lake management of Wuliangsu Lake.[Methods] According to the routine monitoring data and experimental data in Wuliangsu Lake from April 2014 to January 2015, this paper used Excel and SPSS to analyze the factors influencing water transparency of Wuliangsu Lake.[Results] During the April 2014 to January 2015, water transparency of Wuliangsu Lake ranged from 0.17 to 2.74 m with an average value of 0.82 m. The water transparency was higher in south area than in north area. The seasonal variation of the transparency was spring(1.12 m) > autumn(0.81 m) > summer(0.73 m) > winter(0.61 m).[Conclusion] Chlorophyll a is the most important factor affecting the spatial distribution of water transparency which decreases with its increases. The suspended solids is not the important factor on water transparency, pH value is an indirect factors influencing water transparency.