The relationships between target and taxonomic or thematic stimuli of 70 triads were assessed, employing rating scales and factor analysis. Four types of triads were constructed: four triads with high taxonomic and high thematic relations to the taget stimuli (H-H), those with high taxonomic and low thematic relations (H-L), those with low taxonomic and high thematic relations (L-H1, L-H2). These triads were presented to 5-year-olds and adults. Adults responded more taxonomically than children in all triads. Children responded less thematically in H-L than in other three kinds of triads, whereas adults responded more taxonomically in H-H and H-L than in other kinds of triads. The results suggest that (a) children are susceptible to thematic relations, while adults are to taxonomic relations, and (b) knowledge of the concept names common to taxonomic pairs are important to facilitate taxonomic organization.