Existing canal-system water use efficiency (CSWUE) specifically reflects canal engineering conditions impacts on water conveyance efficiency, including the influences of engineering conditions and management level to water use efficiency of canal-system, namely can't distinguish the impacts between engineering conditions and management level to water use efficiency. So, the existing assessment indicator may lead to an excessive emphasis in engineering measures (such as channel lining), such as rational water allocation to raise CSWUE and cannot be scientific developing water-saving irrigation strategy, while ignoring the management measures. In order to analysis the influence factors of engineering conditions and management level respectively to CSWUE, a new assessment indicator system of CSWUE is proposed based on the modified assessment indicators. The new assessment indicator system including canal conveyance efficiency (Eca), canal-system conveyance efficiency (EC), canal-system distribution efficiency(Ed) and water use efficiency of canal system (Ecs). The definitions, connotations and the determine methods for these indicators are given. The rationality of the assessment indicator system is also tested by case study. Eca is the ratio of net outflow to gross inflow of a certain canal under normal operation conditions. EC is the ratio of net outflow to gross inflow of a canal-system under normal operation conditions during an irrigation period. Ed is the ratio of net inflow to the fields to net outflow from a canal system under normal operation conditions during an irrigation period. Ecs is the ratio of net inflow to the fields to gross inflow from a canal system under normal operation conditions during an irrigation period. Eca and EC revealed the impacts of engineering conditions to water use efficiency, and can be determined by still water measurement or dynamic water measurement methods. Ecs revealed the impacts of engineering conditions and management level to water use efficiency, and can be determined by the ratio of net outflow and gross inflow of a canal-system, or determined by irrigation efficiency divided by field water use efficiency. Ed revealed the impacts of management level to water use efficiency, and can be determined by Eca divided by Ecs. The new assessment indicator system can satisfy the needs of different development stages of irrigation system and different purposes of canal-system water use efficiency assessment, and propose the guide for irrigation project investment allocation, engineering operation and water management assessment.%为分析评价灌区工程状况、管理水平等不同因素对渠系水利用效率的影响，该文对传统渠系水利用效率指标体系作了修正，提出由渠道输水效率、渠系输水效率、渠系配水效率、渠系水利用效率组成的灌区渠系水利用效率指标体系，并分别给出了这些指标的定义、内涵及其确定方法，结合实例分析了该指标体系的合理性。渠道输水效率（Eca）及渠系输水效率（Ec）主要反映灌区渠系工程状况对水利用效率的影响，可由静水法或动水法直接测定某级渠道的渠道输水效率，然后采用各级渠道输水效率连乘的方法确定渠系输水效率；渠系水利用效率（Ecs）综合反映了渠系工程状况和用水管理水平对水利用效率的影响，采用首尾测算法直接得到，也可由灌溉水利用效率除以田间水利用效率间接分析得到；渠系配水效率（Ed）主要反映灌区管理水平对水利用效率的影响，在求得渠系水利用效率和渠系输水效率后，由渠系水利用效率除以渠系输水效率得到。该文所构建的指标体系能满足灌区不同阶段、不同目的开展的渠系水利用效率评价需求，为灌区工程投资分配决策、工程运行状况及用水管理水平评价提供依据。
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