The security of alternative water resources have become a very important part in the water resources researches. Among various water resources, reclaimed water are becoming objects of interests as stable water sources that will replace agricultural, industrial and public supply water owing to high quality and comparatively predictable capacity. Since pilot projects of water reuse have been progressing after 2006, corrosion characteristic analysis on reclaimed water or corrosion influences by pipe types is insignificant. So, this study investigated corrosion characteristics by pipe types of reclaimed water through loop test. Also, the study evaluated influences on the corrosion of internal pipes qualitatively by utilizing corrosion indices. As a results, the assessment of corrosiveness by corrosion indices showed that depending on the characteristics of water quality, the assessment of LSI and KWI showed a result different from the assessment of LR. It was because LSI was based on the deposition of calcium carbonates, whereas LR was based on sulfate ion, chlorite ion, and alkalinity. However, Reclaimed water gets more impact from the corrosion accelerating factors than the corrosion inhibiting factors. Based on such reason, KRWI, which is appropriate to the water quality characteristics of reclaimed water, had been developed and suggested.