In mammals, the oviduct is where a new life initializes with a series of reproductive events taking place, including gametes transport, fertilization, and embryo transfer. A disruption of any of these processes could lead to reproductive disorders, such as infertility. However, a significant lack of the knowledge in the dynamic aspect of these processes have left the etiology of these disorders poorly understood, limiting the efficiency and effectiveness of corresponding clinical management. Although dynamic assessment of the reproductive events in the mammalian oviduct is greatly desired, available imaging techniques are largely restricted with in vitro and ex vivo conditions, not suitable to pursue the tissue and cell dynamics due to the absent of native bioenvironment. Here, we present an in vivo imaging approach capable to probe the mouse oviduct and the reproductive processes inside in a high-resolution, 3D, dynamic, functional, and quantitative fashion. Optical coherence tomography (OCT) is combined with a dorsal imaging window to achieve imaging access to the whole oviduct. With volumetric OCT imaging, we report the detailed structure of the oviduct, sub-cellular visualization of the oocytes, zygotes, and preimplantation embryos, as well as their dynamic movements. Through developing functional OCT imaging methods, we demonstrate micro-scale mapping of the oviductal cilia beat frequency, enable 3D tracking of the sperm, and obtain interesting sperm behaviors at the fertilization site. These results indicate the OCT-based imaging approach can be a useful tool for mammalian reproduction research and will ultimately lead to new discoveries in the field of reproductive biology.