A series of chain branched 1,3-dibenzylthiourea derivatives were designed, synthesized, and evaluated for their antagonist activity against TRPV1. The synthesized chain branched 1,3-dibenzylthioureas 9a-g were tested for their antagonist activities against TRPV1 by $^{45}Ca^{2+}$-influx assay using neonatal rat cultured spinal sensory neurons. Fluorinated ethyl-branched analog 9g showed the most potent antagonist activity with an $IC_{50}$ value of $0.41{mu}M$, but all of the chain branched analogs were less potent than the parent compounds MK-056 and SC-0030, indicating that chain branching on the benzylic position of B-ring is detrimental to potency. Optimized receptor binding seems to be interfered by chain branching, and resulted in decrease in potency.