The influence of the boron content on the various properties of Ni-B alloy films produced by electrodeposition was investigated. The considerable reduction in grain size was observed with increasing boron content. The internal stress was tensile and increased linearly with increasing boron content. Hardness increased up to $750H_{v}$ at 2 at% boron and then kept the value to 11 at% boron for as-plated Ni-B coatings. The hardness of Ni-B films increased up to $1,250H_{v}$ due to the intermetallic$ Ni_3$B precipitation by the heat treatment, and maximum hardness of each coating increases with boron content. Wear resistance decreased with increasing the boron content because of high friction coefficient and brittle fracture of film which has higher content of boron.