Bridge crane is one of the most widely used cranes in our country, which is indispensable equipment for material conveying in the modern production. The most important indicator of crane performances is energysaving. So it is of importance to research on the bridge cranes energysaving assessment. Thus the establishment of assessment index system is a necessary task. Rough set theory is applied widely for researching on incomplete and uncertain information processing. Through reducing the properties by rough set theory, redundant properties are removed and an optimized index assessment system can be obtained.In this paper,establishing the index system of the bridge crane based on the full life cycle of the bridge crane firstly. Secondly,defining the decision attribute and the condition attributes. Thirdly,using rough set theory to reduce the index system of the bridge crane.Finally,an optimized index assessment system of the bridge can be obtained. The research lays the foundation for solving weight for the next step. DOI: http://dx.doi.org/10.11591/telkomnika.v11i12.279