This article explored the effect on improvement of skin on the back of hands, focused on women in their 40s,50s and 60s who begin to suffer from aging, and conducted a 12-weeks dietary experiment to 10 persons in each group, by categorizing into complex diet group of collagen+vinegar(C+V), single diet group of collagen(C),single diet group of vinegar(V) and control group(Cont). The results were as follows; Oil on the back of her hands of C+V group increased 1.6, 6.0 times that of C or V group, respectively. Melanin on the back of her hands of C+V group decreased 2.2, 4.3 times that of C or V group, respectively. Erythema on the back of her hands of C+V group decreased 3.1, 4.1 times that of C or V group, respectively. Callus on the back of her hands of C+V group decreased 4.5, 2.2 times that of C or V group, respectively. Furthermore, as for skin color on the back of hands, C+V group took a turn for the better than other groups. As for wrinkle on the back of hands, C group and C+V group took a turn for the better, but, C+V group was smoother than other groups. As confi rmed by the above results, complex diet of collagen+vinegar had a greater effect on improvement of skin on the back of hands of the women in their 40s, 50s and 60s, comparing with single diet of collagen or vinegar.