This study explores how contextual factors affect the instructional reaction of teachers to the changes in the high-stake testing. The results obtained from an investigation of 11 teachers from five senior middle schools show that contextual factors can be categorized into three, namely, traditional exam culture, leadership at district and school levels, and teachers and students' background at the classroom level. These results elucidate the idiosyncrasies of Chinese exam culture, as well as the complicated effects of other crucial contextual factors.