Basic dye such as cyanine dyes is poorly adsorbed on silver bromide, silver sulfide and silver in the presence of silver nitrate, and well adsorbed on these adsorbents in the presence of potassium bromide. On the contrary, acid dye such as orange II is well adsorbed on silver bromide, silver sulfide and silver in the presence of silver nitrate, and poorly adsorbed on these adsorbents in the presence of potassium bromide. The adsorption of neutral dye such as merocyanine having a strong dipole moment on silver bromide, silver sulfide and silver always increases by both the presence of silver nitrate and that of potassium bromide. These results have been explained by the assumptions that silver bromide, silver sulfide and silver were positively charged when the surrounding solutions contain silver nitrate, and negatively charged when the solutions contain potassium bromide. Also, cyanine dyes are equally well adsorbed on silver bromide, silver sulfide and silver in the presence of potassium bromide.