Abstract: MoS2 thin film was deposited on silicon by deoxidizing tetrathiomolybdate at cathode. With optical microscope, SEM, AES and atom force microscope, structure of film was characterized, and tribological performance of electrodeposited MoS2 such as micro-friction and adhesive energy was studied by AFM. Results show that thin film was composed of molybdenum, sulfur and oxygen and was amorphous. MoS2 thin film of nano/submicro meter thickness was smooth and compact, and with good adhesion to substrate. MoS2 thin film of micrometer thickness was a litter more rough and was easily to crack, causing adhesion. Electrodepositing MoS2 film reduced micro friction of Si surface by about 50% at most. Electrodepositing MoS2 also reduced the adhesive energy by 50%. Decrease of adhesive force was the main reason of lower friction force.