This article examines international students' cultural adaptation at a major national university in China. A survey was designed to measure international students' adaptation to the Chinese sociocultural and educational environments in terms of five dimensions: (1) cultural empathy, (2) open-mindedness, (3) emotional stability, (4) social flexibility and (5) language proficiency. International students (n = 330) from 57 countries participated in the survey. The findings here support the existing proposition that the first year is the critical period for cultural adaptation as there are significant changes in some adaptation indicators (especially emotional stability) over the first year and thereafter changes in these indicators became less and less significant. The present study discusses the adequacy of existing theories in explaining these results and their implications for international students' adaptation as a culture-specific experience in China.