Objective To explore the method of detecting penile somatosensory evoked potential (SEP) in beagle dogs under general anesthesia and the changes of SEP during the process of dorsal penile nerve resection as reference material for further study. Methods Glans penis (GP) and dorsal penile nerve (DN) SEP were measured under general anesthesia and during resection of the dorsal penile nerve in five beagle dogs. The waveforms and parameters were observed. Results Stable waveforms of penile SEP were obtained under general anesthesia in beagle dogs. The average latency of GPSEP was 41. 84±1. 41 ms with an average amplitude of 1. 56±0. 26 μV, while the average latency of DNSEP was 33. 46 ±2. 45 ms with an average amplitude of 1. 80±0. 52 μV. The latency of penile SEP changed significantly during the process of resection of the dorsal penile nerve in the dogs ( P < 0. 05). Conclusions Detection of penile SEP under general anesthesia is feasible and its waveform is stable. There are changes in the latency of penile SEP during the process of resection of the dorsal penile nerve, which can provide an experimental animal basis for further study of the treatment of erectile dysfunction and premature ejaculation.