This paper describes an ethylene glycol (EG)-assisted approach to the large-scale ultralong Sb2S3 sub-microwires, formed by a simple hydrothermal reaction between SbCl3 and Na2S in the presence of distilled water. Transmission electron microscopy and scanning electron microscopy studies indicate that these Sb2S3 sub-microwires possess a diameter around 200nm and length up to 100μm. High-resolution transmission electron microscopy and selected area electron diffraction studies reveal that each Sb2S3 sub-microwire is a single-crystal along the [001] direction. The possible formation mechanism of the sub-microwires was discussed. The effects of volume ratio of EG/water, reaction temperature and the concentration of CO(NH2)2 on the morphology of Sb2S3 sub-microwires were also investigated.