Abstract: Alpaca is one of the most important hair-producing animals. However, the genetic regulation of the growth of alpaca hair is largely unknown. Here, we report a surprising finding that prolactin (PRL), PRL receptor (PRL-R) and other PRL related genes were expressed in the male alpaca skin. The expression levels of PRL in the skin were relatively lower than that in pituitary gland. The PRL and its receptor protein were detected in root sheath of hair follicles, epidermal and sebaceous gland of alpaca. The expression of PRL and PRL-R in the male alpaca suggested that PRL may regulate the growth of alpaca hair through an unknown mechanism in addition to its established role in milk production.