This study explores the relationships among Taiwanese high school students' scientific epistemic beliefs (SEBs), conceptions of learning science (COLS), and motivation of learning science. The questionnaire responses from 470 high school students in Taiwan were gathered for analysis to explain these relationships. The structural equation modeling technique was utilized to reveal that the students' absolutist SEBs led to reproduced COLS (i.e. learning science as memorizing, preparing for tests, calculating, and practicing) while sophisticated SEBs were related to constructive COLS (i.e. learning science as increase of knowledge, applying, and attaining understanding). The students' reproduced COLS were also negatively associated with surface motive of learning science, whereas the constructive COLS were positively correlated with students' deep motive of learning science. Finally, this study found that students who viewed scientific knowledge as uncertain (advanced epistemic belief) tended to possess a surface motive of learning science. This finding implies that the implementation of standardized tests diminishes Taiwanese high school students' curiosity and interest in engaging deeply in science learning.