In an 8-wave, 4-year longitudinal study, 787 children (Grades 3-6) completed the Revised Children's Manifest Anxiety Scale (C. R. Reynolds & B. O. Richmond, 1985), a measure of the Physiological Reactivity, Worry-Oversensitivity, and Social Alienation dimensions of anxiety. A latent variable (trait-state-occasion) model and a latent growth curve model were applied to each of the 3 anxiety dimensions and to a general anxiety factor consisting of the 3 dimensions. Although the general anxiety factor reflected a significant stable trait process, the Worry-Oversensitivity and Social Alienation dimensions reflected an autoregressive process more than a stable trait dimension. In contrast to the other 2 anxiety dimensions, Physiological Reactivity reflected a significant stable trait process, suggesting that the longitudinal structure of anxiety in children depends upon the dimension assessed. In children as early as age 9 or 10, Physiological Reactivity (more than other anxiety dimensions) manifested a stable trait component. Structural findings were consistent across gender and race; however, mean differences in gender and race emerged for general anxiety and its 3 dimensions. (Contains 3 footnotes, 6 tables, and 2 figures.)