Intraspecific chemical communications are documented in animals from single-celled organisms to nonhuman mammals. Increasing behavioral studies and recent brain imaging studies using positron emission tomography point to the existence of chemical communications in humans. Using functional magnetic resonance imaging, we examined whether the brain differentiates between human-related smells (sweat of sexual arousal, sweat of neutral emotion, and putative human sex pheromone androstadienone) and their non-social control (phenyl ethyl alcohol or PEA) after controlling for differences in the perceived intensity and pleasantness of the smells. With PEA as the reference point, we identified a region in the right fusiform gyrus which showed strong activation to the sweat of sexual arousal and little response to the putative sex pheromone. Our result suggests the right fusiform recognizes the human quality associated with the sweat of sexual arousal. Keywords. Chemical communication, fMRI, fusiform, human body odor