As an increasing number of international students are studying in English-speaking universities, there has been growing interest in exploring the factors and complexities that impact international students' academic achievement and adaptation during their studies. The present study aimed to investigate how international students adapt to new academic environments in US universities by exploring the relationships between self-determined motivation, beliefs about classroom assessments, the use of self-regulatory learning strategies, and academic performance based on self-determination theory. To examine international students' learning experiences, 321 international Asian undergraduate students at a large research-intensive midwestern university participated in an online survey. Structural equation modeling was conducted to test the proposed model. The findings demonstrated that self-determined motivation in courses led to adaptive beliefs about classroom assessments, which promoted a variety of self-regulatory learning strategies, including shallow and metacognitive strategies. Metacognitive learning strategies were significantly related to students' academic performance. This study allows us to better understand how Asian international students adapt to US academic environments through their motivation to learn, perspectives about classroom assessments, and learning strategies across different academic disciplines at the university level.