The comprehensive index assessment method based on the state-pressure-response index systems was applied to establish the eco-security assessment index systems of the water environment of Changsha-Zhuzhou-Xiangtan district, and through the index system, the eco-security of the water environment was evaluated according to 2004-2008 statistical data. The assessment results have shown that the synthetical index value for the security assessment of the water environment in Changsha-Zhuzhou-Xiangtan district presented a low level except in 2006, and it was in the warning condition, and the assessment value of the state has been decreasing in these years, which indicated that the eco-system of the water environment in Changsha-Zhuzhou-Xiangtan district has been damaged continuously and the proportion of response index was the smallest among the researched indexes. Therefore, the efforts on the eco-system construction of the water environment should be intensified in the coming years.