This study followed the comparative research mode of description, interpretation, juxtaposition and comparison. Based on the literatures and data collected on the topic, the paper compared and analyzed the past, present and future of APTHS (academic proficiency test for high schools) in the two countries. Some contemplations on the common issues faced by many countries were also discussed. Compared with U.S., the status quo of the exam in China is more problematic resulting from its low professionalization on test assessment and measurement, and bureaucracy on the exam administration. For both countries, equity is the utmost concern in the future development and reform of the exam. (Contains 6 figures and 2 tables.) [This research has been funded by the No. 51 China Postdoctoral Science Foundation.]