Despite the wide application of general anesthetic drugs in clinic, it is still unclear how these drugs induce the state of general anesthesia. Larval zebrafish has emerged as an ideal model for dissecting the mechanism of neural systems due to the conserved and simple brain structure. In the present study, we established an anesthesia model from behavioral to electrophysiological levels using larval zebrafish for the first time. Bath application of etomidate, as a kind of intravenous anesthetic drugs, suppressed the spontaneous locomotion of zebrafish in a concentration-dependent manner. Consistently, in vivo fictive motor patterns of spinal motoneurons recorded extracellularly were significantly inhibited as well. Furthermore, using in vivo extracellular recording and whole-cell recording, we found that etomidate application suppressed local field potentials (LFP) of the brain and blocked visually evoked responses of optic tectal neurons. The study indicates that larval zebrafish can serve as an ideal vertebrate animal model for studying neural mechanisms underlying general anesthesia.