Cerebrospinal fluid (CSF) flow is crucial for brain homeostasis. Among various methods to modulate CSF flow, focused ultrasound stimulation (FUS) has been reported to enhance CSF circulation. However, real-time in vivo observations of FUS targeting the skull base are scarce. We have shown a novel method of directing FUS towards the skull base, demonstrating that it can facilitate CSF influx, as evidenced by various in vivo imaging techniques. Male C57BL/6 mice aged 8-10 weeks were intraperitoneally injected with a mixture of Zoletil and xylazine for anesthesia and exposed to the atlanto-occipital membrane for cisterna magna cannulation. For macroscopic imaging, the entire skull was exposed, and applied mineral oil to ensure transparency. For two-photon imaging, a craniotomy was performed on the primary somatosensory cortex and a cover glass covered over the exposed dura. We injected CSF tracers into the cisterna magna, using 10 µl of 0.5% FITC 2000kDa or microspheres. FUS was administered at the midline of the jaw targeting the skull base for 30 minutes. The enhanced CSF influx observed in macroscopic imaging was corroborated by the area and intensity of the CSF tracers after FUS. In two-photon imaging, increased fluorescence was observed within the imaging field post-stimulation. Moreover, particle tracking of microspheres showed that a greater number of microspheres entered the imaging field, and the average velocity of the microspheres also increased. Altogether, our findings demonstrate that FUS promotes CSF influx, as confirmed by in vivo imaging.