中文摘要：

基于“压力-状态-响应（PSR）”模型，运用能值分析方法构建了城市生态安全评价体系和城市生态安全指数（EUESI），并评价了1995-2005年间唐山市生态安全水平的变化．结果表明：1995-2005年间，唐山市生态安全水平呈先升高后降低的趋势；基于能值分析的研究区城市生态安全指数由1995年的0．017增加到1996年的0．022后逐年降低，2003年进入不安全状态．基于能值分析的城市生态安全评价方法克服了传统评价体系的指标繁多、重复、单位不统一和可比性差等缺点，更加真实客观地反映了城市生态安全状态，为城市生态环境的管理和决策提供了科学依据．

英文摘要：

Based on‘pressure-state-response＇ model and by using emergy analysis method, the urban ecological security assessment system and urban ecological security index （EUESI） were construeted, and the variation of ecological security level of Tangshan City in 1995-2005 was evaluated. During this period, the ecological security level of the City increased first and decreased then. The EUESI increased from 0. 017 in 1995 to 0. 022 in 1996, then dropped yearly, and beeame unsecure in 2003. The urban ecological security assessment method based on emergy analysis overcame the disadvantages of conventional assessment system, e. g. , numerous and repetitive indicators, non-uniform units, and poor comparability, and reflected the urban ecological security state more objectively, being able to provide scientific basis for urban ecological environment management and decision-making.