Objective The in situ hybridization method was used with signal amplification system for detecting G-protein expression in taste buds. Methods The gene of gustducin and ?- rod transducin in rat are cloned by RT- PCR. Their sense and antisense probes were labeled with digoxigenin. About 150 taste buds in rat vallate and foliate papillae were analyzed. Results The results showed that there were 1.2 transducin-positive cells and 6.2 gustducin-positive cells counted in each taste bud profile on average. The number of gustduin-positive cells was approximately five times more than transducin-positive cells in taste buds. There were 4. 1% gustducin-positive cells and 0.8% transducin-positive cells in all taste cells. It could not be seen any cross reation of transducin probe to gustducin target. The high expression of transducin in retina was also observed but no gustducin expression could be detected. Conclusion The result of present study proved that both transducin and gustducin were taste G-protein and gustducin was high expressed. Both of them might be involved in taste signal transduction.