This study has examined the improvement of hair damage and retaining effect of hair conditioner using the extract from Camellia japonica leaves and stems, which have long been used as the ingredient of cosmetics and hair oil thanks to high-quality fat and rich protein content. In terms of research method, healthy hair was bleached three (3) times in total. Then, the degree of hair damage was measured. The recovery of hair damage has been compared through hair conditioning on the organic solvent extract of Camellia japonica and control group. Then, the following results were obtained: 1. In case of healthy hair, diameter was 0.1 ㎜ in average, and tensile strength was 14.5-15.2 g/d. 2. The diameter of hair decreased by 19.0%, 25.0% and 31.6% at once, twice and three times of hair bleaching respectively. Tensile strength also decreased by 8.2%, 21.7% and 26.2% at once, twice and three times of hair bleaching respectively. Hence, it’s been confirmed that hair damage increases as bleaching proceeds. 3. After hair-conditioner treatment on bleached hair, the diameter of hair increased by 13.1% in a control group and by 20.2% in Camellia japonica extract when hair was bleached once. When hair was bleached twice, it increased by 13.7% and by 25.0% in a control group and in Camellia japonica extract respectively. When hair was bleached three times, the diameter increased by 14.4% and by 25.0% in a control group and in Camellia japonica extract respectively. 4. After hair-conditioner treatment on bleached hair, tensile strength increased by 16.2%in a control group and by 18.1% in Camellia japonica extract when hair was bleached once. When hair was bleached twice, it increased by 22.5% and by 26.6% in a control group and in Camellia japonica extract respectively. When hair was bleached three times,the tensile strength increased by 22.9% and by 28.7% in a control group and in Camellia japonica extract respectively. According to the results above, both hair cleaning and retaining effects of Camellia japonica extract were higher in a control group, which means that Camellia japonica extract is effective in caring damaged hair. It is expected that the results of this study would be used in developing hair conditioners using natural extracts. In addition, they could be used in developing other Camellia japonica extract-contained products.