This research was to evaluate conservational stability of cleaning treatment and color recovery by weak acid treatment on ivory. Before this experiment, had an ivory identification such as black light and schreger angle to find whether it is authentic or not. In wet cleaning treatment on ivory, used polar solvents such as distilled water, acetone, ethyl alcohol and acetic acid which usually used for cleaning ivory and bones. After cleaning took a experiment to evaluate conservational stability in surface observation, calculate weight and color difference. Following these results, these polar solvents were stable on the ivory samples. On the other hand, in weak acid treatment, used samples that were exposed by UV-A, UV-B, UV-C for 1 weeks, to restore its color from changed to original color. After treatment, found tiny cracks and exfoliation on the surface. Moreover, the color changed when it is treated by lemon juice, so, it is impossible to adapt.