To provide a tension member for communication cables, which has high adhesion to another member and excellent pullout strength, has sufficient strength and can be manufactured at low cost; and to provide a method of manufacturing the same.

A tension member 1 has a polyester resin monofilament as a component element and is used as an internal reinforcing member of a communication cable, and the polyester resin monofilament has deformed cross-section portions 2 and non-deformed cross-section portions 3 alternated consecutively along its lengthwise direction and has an concave-convex outer shape where a ratio a/b of a longer diameter a to a short diameter b of the deformed cross-section potions 2 is 1.2 to 4.0 and circumscribed circle diameters of the non-deformed cross-section portions 3 are 0.2 to 5.0 mm.