The development of a research model to aid in the understanding of the hierarchical structure of reading readiness is described. Data were obtained by testing 218 first graders from three elementary schools with the Frostig Developmental Test of Visual Perception, the Gates Reading Readiness Test, the Metropolitan Readiness Test, the Olson Reading Readiness Tests, and the Wechsler Intelligence Scale for Children. The product moment method was used to compute the intercorrelations among the 35 variables. After an examination of the loading of the subtest variables, four large common factors, listed in order of increasing correlation with the factor best representing reading achievement, could be ordered as follows: (1) perceptual organization, (2) auditory-visual discrimination, (3) verbal association, and (4) verbal comprehension. Both a horizontal and a vertical plane were developed in this model. It is suggested that the order of the skills on the vertical plane would also develop horizontally and might or might not contribute to the achievement level of a higher order dependent upon the type of achievement measured. Questions for further investigation are posed, and references are included. (CM)