Muskrat （Ondatra zibethicus）musk is known as the best natural substitute for musk from musk deer. Muskrat musk is produced by the scent glands of the male muskrat reproductive system in spring. The glandular cells and stroma (supporting) cells are the key cells for secretion of muskrat musk. This study investigated the development stages of muskrat scent glands through the techniques of histomorphology, immunohistochemical staining and immunofluorescence. Histological and immunohistochemical staining showed that the scent glands were rich in small, rounded acini (secretory units) at the initial stage, where both the androgen level and number of the secretory cells in the scent glands were at a minimum. Coincident with the development of the scent glands, the acini became gradually bigger, and the androgen level and number of the secretory cells increased, reaching a maximum in two months. By the end of the developmental stage, the acini were atrophied and replaced by connective tissue. We further isolated and characterized the secretory

cells and supporting cells. We believe that our results have laid the foundation for constructing an in vitro system for the production of musk, which would help mitigate the short supply of musk in the market.