PURPOSE: To obtain the subject yarn capable of easily giving a wiping cloth having excellent cleaning power, durability, workability, feeling, etc., by supplying a specific ultrafine crimped yarn and a specific multifilament yarn to the same disturbance nozzle under specific condition and subjecting the fibers to fluid treatment.

CONSTITUTION: The objective yarn having loop fluffs composed of an ultrafine crimped yarn on the yarn surface can be produced by preparing (A) an ultrafine crimped yarn produced by the simultaneous drawing and false-twisting of a highly oriented undrawn polyester yarn having a single fiber fineness of ≤0.8d and a birefringence of 3×10-3-130×10-3 at a low draw ratio and (B) a polyester multifilament yarn having a single fiber fineness and a boiling water shrinkage larger than those of the yarn A and feeding the yarns A and B to the same fluid-disturbance nozzle while keeping the feeding rate of the yarn A to be larger than that of the yarn B, thereby subjecting the yarns to fluid treatment. The draw ratio of the yarn A in the simultaneous drawing and false-twisting process is preferably 10-70% of the full draw ratio of the supplied yarn.