Abstract: A driving shaft includes yokes at both its ends and an intermediate slidable portion composed of a male shaft member and a female shaft member fitted with each other by means of splines. The male shaft member includes a hollow shaft member having an inner diameter larger than the outer diameter of one end of the female shaft member on the side of the male shaft member, and a splined male member having a splined slidable portion to be fitted in the splined hole of the female shaft member and a fixing portion fitted in the hollow shaft member. An elastic body interposed between the inner surface of the hollow shaft member and the outer surface of the fixing portion to fix the splined male member to the hollow shaft member. In producing such a driving shaft, before fitting the splined male member in the hollow shaft member, a resin coating is applied to either the inner surface of the hollow shaft member or the fixing portion of the splined male member.