There are several factors that could account for children's phonological awareness ability. Those factors such as phonological units(i.e., syllable, onset-rime, body-coda, phoneme), type of phonological awareness(i.e., isolation, blending, segmentation, deletion, substitution, addition), type of response(i.e., accuracy, rate), characteristic of norm(i.e., age, sex, location of residence, existence of disability, language ability) and parents' status should be taken into account when it is being developed.. Thus, the effect of thses factors on phonological awareness ability of children need to be examined. The purpose of this study is to investigate the influence of parent's social economic status on phonological awareness ability in children when phonological awareness assessment is being developed. Students were sampled from three different school in terms of economic status of residence, such as from low class neighborhood, middle class neighborhood, high class neighborhood. Phonological awareness assessment designed by the current researchers were conducted to each student on one to one basis. Results were following. Children's phonological awareness ability was different according to their parent's social economical status. The kids from poor neighborhood have poor phonological awareness ability while the children from rich environment have higher phonological awareness ability. This means that parents' social economical status can account for some of individual variation of phonological awareness ability. Consequently, developer should consider this fact when he or she develop phonological awareness assessment.