The synaptic connection from high vocal center (HVC) to robust nucleus of the arcopallium (RA) is a pivotal part of vocal motor pathway in songbirds. Electrophysiological properties of HVC-RA synaptic transmission in adult male zebra finch (Taeniopygia guttata) in vivo was investigated by using field potential recording method. Following electrical stimulation of HVC, the evoked field potentials recorded in RA were feeble. The results showed that the remarkable paired-pulse facilitation was induced by paired-pulse stimulation at HVC-RA synapses. The results also showed that the evoked field potentials were significantly decreased after a conditioning tetanic stimulation and finally recovered gradually within 15 min, which indicates tetanic stimulation-induced transient depression is present at HVC-RA synaptic transmission. These results suggest that properties of synaptic transmission in this pathway might play a role in controlling song production.