The loss in weights of silk samples during aging and of aged silk samples immersed in water, alcohol and acetone were researched. The aim of the research was to understand the mechanism of silk aging, and provided evidence for the selection of silk cleaning agents. The results showed that during heat and light aging, the silk samples weights all reduced, and the heat aged samples lost more in water than light aged samples did. The longer the samples were aged and immersed in solvents, the more weights were lost. The alcohol and acetone had less effects on aged silk samples than water did. Therefore, the organic solvents were more suitable for use in washing silk.