Cultural identity affects the fairness of second language(L2)writing assessment in varying degrees.This paper endeavors to explore how the four dimensions of cultural identity influence L2 writing assessment.Ethnic cultural identity affects L2 writing assessment through teachers'levels of lenience towards students,the cooperation modes between teachers and students or among students,and the imbalanced expectations of teachers and students.Regional cultural identity affects L2 writing assessment due to various personal backgrounds,students'education experiences,and teacher training in different regions.Academic cultural identity affects L2 writing assessment owing to diverse academic standards,contexts,and the exertion of creativity.Disciplinary cultural identity affects L2 writing assessment because of different writing patterns,structures of lectures,and focuses of writing.The paper concludes with suggestions for future research on cultural identity and L2 writing assessment.