Located at a meeting place between the West and the East, Hong Kong has been chosen in this comparative investigation to reconfirm a theoretical model of "reciprocal relationship" between mathematics achievement and self-concept using the 8th grade databases from TIMSS and TIMSS-R. During the time between these two projects, Hong Kong experienced a political transition in 1997 to switch from a British colony to a special administrative region (SAR) of China. Pertinent indicators have been selected to reflect key educational changes during the sovereignty handover. Results from this large-scale data analysis may not only help generalize the reciprocal model in a different culture setting, but also facilitate assessment of educational adjustment brought by the political transition. (Contains 4 tables, 1 figure, and 3 notes.)