To provide a string which eliminates such problems as noted in durability, resilience of golf balls and the like by using poly(1,3-propylene terephthalate) fibers as a main component.

At least one of the core yarn and the side yarn is composed of the poly(1,3-propylene terephthalate) fibers. The poly(1,3-propylene terephthalate) fibers are contained at a rate of 20 wt.% to 80 wt.%. The string is adjusted to attain a dynamic hardness of 6,000N to 10,000N. This is expressed by S(N)=0.125f2, wherein f is vibration frequency (Hz) which is derived in the string when one end of a string of 356 mm long is fixed, a weight of 35.7 g is put at the center thereof and the string undergoes single vibration as caused under a tensile force of 267N.