Abstract: The present study was aimed to investigate the existence and distribution of label-retaining cells (LRCs) in mouse oviduct. C57 mice in 3 days old were subcutaneously injected with BrdU (5-bromo-2'-deoxyuridine) twice daily, at 9:00 and 16:00, for 3 consecutive days. After 8 weeks labeling, the oviduct was collected to make frozen section and immunofluorescence staining for detecting the existence of BrdU positive LRCs. The results showed that the BrdU positive cells presented a gradient distribution from the distal (ampulla) to the proximal (isthmus) in oviduct, and these cells were mainly localized in the epithelium. In conclusion, these data suggested that the progenitor cells or stem cells might exist in the epithelium of distal oviduct.