This research examined the extent to which children's understanding of metaphors for the mind relates to their developing theories of mind. Specifically, comprehension of two types of metaphors were examined: Mind as Container (e.g., "I put it out of my mind.") and Mind as Homunculus (e.g., "My mind wandered"). It was proposed that children's conceptualization of the mind as a container is related to their grasp of false beliefs, an important theory of mind milestone that children reach during the pre-school years. It was also proposed that children's understanding of how the actions of the mind are like those of a person is linked to later theory of mind development. One purpose of the initial study was to develop a metaphor comprehension task appropriate for use with children younger than 6. With the new task, the 26 5-year-old participants in Study 1 performed above chance when interpreting Mind as Container metaphors, t (25) = 5.41, p < .001 and some Mind as Homunculus metaphors, t (25) = 2.60, p < .05. These children also understood Mind as Container better than Mind as Homunculus metaphors, F (1,25) = 5.54, p < .01. The primary purpose of Study 2 was to investigate the relationship between children's understanding of Mind as Container metaphors and their performance on false belief tasks. The results from 80 4- and 5-year-olds showed a significant positive correlation between these two variables, after controlling for age, verbal ability, and analogical reasoning, r (63) = .28, p < .05. In Study 3, this relationship was examined experimentally. Over the course of several weeks, children were trained on either Mind as Container metaphors, false belief tasks, or a control task (analogical reasoning). The results indicated that the metaphor training improved children's understanding of Mind as Container metaphors, t (9) = -2.71, p < .05. It also improved performance on a sub-set of false belief tasks significantly more than the control training, F (1, 26) = 7.39, p < .05. The results of this research support the idea that a conceptual Mind as Container metaphor plays a role in children's understanding of false beliefs. (Bayta Maring)