Abstract: Effect of small amount of B on the microstructure and wear resistance of special brass was investigated by means of SEM,abrasion machine etc.The addition of small amount of B increased the amount of α-phase,caused the formation of Mn5Si3 particles,and changed the shape,distribution and size of the α-phase and Mn5Si3 particles.When special brass modified with small amount of B was rubbed,these changes were beneficial to releasing the stress for crack initiation and propagation.Small amount of B caused the formation of dense oxide or compound of B on the surface of abrasion area to abate adherence abrasion,resulting in a significant increase of the wear resistance of the special brass.