Objectives: The aims of this study were to develop Taiwan’s Child Health Literacy Test and to undertake a nation-wide survey in order to determine the current status of Taiwanese sixth graders’ health literacy, and to understand the association between health literacy, healthy behavior, and health status. Methods: Taiwan’s Child Health Literacy Test was developed through the process of concept clarification, a qualitative pilot, a development pilot, and a field test. In the field test, 162,609 sixth graders (56.9%) from 2,235 schools (83.3%) nationwide completed the questionnaire. We also collected the students’ dates of birth, BMIs, self-reported health and healthy behaviors. Results: The final test consisted of 32 questions with item discrimination of 0.55~1.89 and item difficulty of -1.7~0.41 according to IRT; Cronbach’s α was 0.87. Based on this information, the test was deemed appropriate for basic health literacy screening among children. Nation-wide, the average score for sixth graders’ health literacy was 23.97 points (total score 32 points), with a correct rate of 74.9%. Those who were ＂good＂ in self-reported health scored highest in health literacy (M = 24.29). Health literacy was significantly positively related to healthy behavior (r = .25, p ＜ .05), and negatively to risky behavior (r = -.28, p ＜ .05). Conclusions: This study was the first curriculum-based child health literacy test developed from the viewpoints of both teachers and pupils in Taiwan through a rigorous procedure. The nationwide survey results may serve as a reference for decision-makers at the national health education level.