P>Objective To investigate the distribution of nerve growth factor(NGF) and epidermal growth factor (EGF) and their colocalization with follicle-stimulating hormone (FSH) in rat submaxilary glands, and to study the effects of FSH on the secretion of NGF and EGF by submandibular gland tissue in vitro. Methods Immunohistochemical colocalization method was used in the experiment.Submandibular tissues of rats were incubated in vitro and different concentration of FSH was added.Enzyme link immunoassay was used to measure EGF and NGF in supernatant. Results The serous glandular cells, granular convoluted epithelial cells and all other duct epithelial cells in the submandibular gland showed FSH,NGF or EGF positive immunoreactivity.The positive substance was distributed in the cytoplasm with negative nuclei. Both FSH and NGF or EGF positive products were co-located in rat submandibular gland.When the concentration of FSH was more than 10SUP>-5/SUP>-10SUP>-6/SUP>IU/L,the secretion of EGF and NGF lessened with the decreased concentration of FSH; when the concentration of FSH was less than 10SUP>-5/SUP>-10SUP>-6/SUP>IU/L, the secretion of EGF and NGF increased with the decreased concentration of FSH. Conclusion FSH has the same bidirectional regulation effects on EGF and NGF EM>in vitro./EM> FSH may regulate the function of endocrine of rat submandibular gland. /P>