Ultrasound (US) brain stimulation has been demonstrated to be a promising approach for noninvasive neuromodulation. However, traditional methods always demand animals to be under anesthesia and body constraint to achieve stable operation with bulky US transducer, while those demands would result in interference to the neural activity related to perception, cognition, and behavior. Appling a miniature US stimulator on freely moving mouse will greatly benefit for obtaining credible neural response from ultrasonic neuromodulation. This study investigates the local field potentials (LFPs) responses to ultrasonic neuromodulation on freely moving mouse by using a customized head-mounted US transducer.