PURPOSE: To form a Ni-B coating excellent in wear resistance on a base material, by dipping the base material for plating in a plating solution containing a water-soluble Ni salt, a chelating agent, an alkali metal hydroxide, a boron- containing reducing agent, and ethylene thiourea, at the time of Ni-B electroless plating.

CONSTITUTION: As the electroless plating solution used for forming the Ni-B coating on the surface of the base material to be plated such as steel, Ti, Ni, Cu, Al, Mg by electroless plating method, an aq. solution containing 0.01-0.15mol/l water-soluble Ni salt such as nickel sulfamate, a chelating agent such as ethylene diamine in a quantity to be the molar ratio to the Ni salt in the range of 4/1 to 12/1, an alkali metal hydroxide in a quantity to given pH12-14 in the plating solution, 0.002-0.052mol/l boron-containing reducing agent and (0.098-9.8)×10-5mol/l ethylene urea, and at a temp. of 185-215°F is used. The Ni-B coating excellent in wear resistance is formed on the base material by electroless plating method.