Using the PSR model, this article has build the evaluation index of the ecological security system, applied the entropy method to define the weight of each assessment index, and applied the intimate data method for evaluating ecological security of Fuzhou Shanzi Reservoir. The results showed that the ecological security situations during 2000 to 2003 from superior to inferior states were in the sequences of 2002, 2001, 2000 and 2003 in Shanzi Reservoir, Fujian Province. The model was simple calculation, objective description and comprehensive reflection of the sample position. The index system was more completely reasonable in needs of the reservoir ecological environmental protection objectives.