The elemental composition and chemical states of the surface film of silver-electroplated deposits with different treatment and aging time have been investigated by means of XPS and AES. The results showed: ( 1 ) Fresh deposit U0

stored indoors in a transparent desiccator for 5 days

was composed of the elements silver

oxygen

sulphur

chlorine and the matrix metal copper in addition to contaminating elements carbon

potassium and nitrogen; the content of elemental silver of a series of untarished deposits U0 and U1 decreased steadily with time

while elemental oxygen increased almost linearly. ( 2 ) The distributions of the elements silver and oxygen of deposit U1

treated with NaCl solution

were the same in Auger line scan

but for deposit U2

treated with Na2S solution

the coexistence regions of the elements silver and sulphur partly replaced those of silver and oxygen.The atomic ratio of S/Ag differed with the treatment of the silver deposit. The ratios for deposit U3

stored indoors in a transparent desiccator for 500 days

and for deposit Ts

stored indoors in a transparent desiccator containing air with 1% H2S for 24 hours

were much greater than that for deposit T1 which is exposed to sunlight outdoors for 24 hours. ( 3 ) The two dimensional Auger parameter plot showed that Ag2O amounted to 19% of the total silver in deposit T1

and was practically nil in deposit U0. (4) The anti-tarishing ability of fresh deposit increased markedly after treatment with certain reducing or complexing agents. Based on these results

the tarnishing mechanism and anti-tarishing principle were discussed.