This study evaluated the effectiveness and safety of an experimental bleaching strip (Medison dental whitening strip, Samsung medical Co., Anyang, Korea) containing 2.9% hydrogen peroxide. Twenty-three volunteers used the bleaching strips for one and a half hour daily for 2 weeks. As control group, the same strips in which hydrogen peroxide was not included were used by 24 volunteers with the same protocol. The shade change (ΔE*, color difference) of twelve anterior teeth was measured using Shade Vision (X-Rite Inc., S.W. Grandville, MI, USA), Chroma Meter (Minolta Co., Ltd. Osaka, Japan) and Vitapan classical shade guide (Vita Zahnfabrik, Germany). The shade change of overall teeth in the experimental group was significantly greater than that in the control group (p < 0.05) and was easily perceivable. The change resulted from the increase of lightness (CIE L* value) and the decrease of redness (CIE a* value) and yellowness (CIE b* value). The shade change of individual tooth was greatest in canine, and smallest in central incisor. The safety of the bleaching strip was also confirmed.