Twenty-seven N, N′, N ″-trisubstituted thiourea derivatives were prepared. Among them, 1- [3-(4′-hydroxy-3′-methoxy-phenyl)-propyl]-1, 3-diphenethyl-thiourea (8l, IC50= 0.32 μM), showed 2-fold higher antagonistic activity than that of capsazepine (3, IC50= 0.65 μM) against the vanilloid receptor in a 45Ca2+-influx assay.