This study examined changes of test anxiety under the reform of the examination system in Taiwan. We sampled 46,361 Grade 9 students in Taiwan for 9 consecutive years starting from 2011 to collect data on their test anxiety, cram school attendance frequency, and academic achievement. Students' test anxiety level was compared between three periods: Basic Competence Test (2011-2013), Comprehensive Assessment Program (CAP 1; 2014-2016), and CAP 2(2017-2019). The results indicated that first, during CAP 1, students' test anxiety increased, but decreased in CAP 2. Second, the test anxiety level of students those with an upper-intermediate level of academic achievement, increased. Finally, the cram school attendance frequency didn't differ among the three periods. We provide suggestions for countries with a similar social climate. For potentially controversial social issues, such as test anxiety, policy makers should develop corresponding measures in advance on the basis of empirical evidence.