The highway bridges required the maintenance have been consistently increased over 8,000. For long term maintenance strategy, it should be focused on utilizing the systemic information from in-depth inspection data. From now, record-based inspection for highway bridges has been usually performed so that it is needed to investigate the in-depth inspection data for identifying the damage characteristics in detail. In this study, with respective to the performance measure of damage characteristic, damage normalization of highway bridges is researched by using the suggested bridge scales such as area, length, vertical distance, number of members. Based on this process, the standard cost for various damages for highway bridges can be estimated and utilized for long-term maintenance strategy.