This paper have studied the high temperature frictional wear properties of Ni-P coatings on 20CrMo steel manufactured by electro-brush plating. A ball-on-disc configuration with no lubricants was employed and 4 mm diameter Si3N4 ball was used as static counterpart. The results showed that with the coating time increased from 0 to 24 minutes, the overall average friction coefficient and the mass worn loss of specimens were both declined in the wear test at 450 oC for 180 minutes. The wear became slighter as the coating time increased. When the coating time were 0, 6, 12 and 18 minutes, the main wear form of samples were deep microscopic plough cutting and spalling failure. As the coating time increased to 24 minutes, its main wear form were shallower microscopic plough cutting, almost no spalling failure.