This research aims to evaluate the effects of dopamine as a link in the hydrophobicity of carbonyl iron particles with stearic acid. In this connection, the effect of stearic acid and oleic acid on the hydrophobicity of carbonyl iron was also investigated. For this purpose, the FESEM analysis was used to observe the surface modification of the particles, and the surface structure of the particle was studied. Also, the magnetic properties of hydrophobic particles were measured by VSM and Magnetic saturation of CI, CI @ Stearic acid and CI @ Dopamine @ Stearic Acid is 200, 169, 131 emu/g respectively, in which this decrease is not significant. Finally, the contact angles of samples were measured. Basing on the result, the static contact angle of a water drop placed on a bed of the CI @ Oleic acid, CI @ Stearic acid, and CI @ Dopamine @ Stearic Acid were found to be 156.2°, 162.9°, and 169.022° respectively. The result showed that dopamine has a good effect as a link to the hydrophobicity of particles.