本研究通过对比中美同伴反馈类型的分布、出现频率和学习者对评论的反思，调查跨洋互动写作活动中的中美同伴反馈类型。数据包括同伴反馈文本、修改报告和后续访谈，分析显示，中美同伴的总体反馈类型并无明显差异，均为指正性反馈数量最多，肯定性反馈次之，其他类型反馈最少。然而，双方反馈类型的出现频次存在显著性差异，主要体现为批判与读者友好、权威对话与平等对话和静态文本与动态话语等三个方面。

 As one of B-learning practice, mixed peer response groups consisting of both native English speakers and English as a Second Language (ESL） students are often seen in mainstream ESL composition classes. A few researchers have examined the effects of peer feedback on writing skills, language and cultural awareness of ESL students in mixed groups, but little research has explored the similarities and differences of peer feedback types in a mixed group. The study investigates Sino-US peer feedback types in a Cross-Pacific online exchange by contrasting their distributions and frequencies as well as learners’ reflections around feedback. Data included peer feedback discourses, review reports and a follow-up interview, which reveals no significant differences of peer feedback types between Chinese learners and American learners, showing critical feedback the largest, followed by affirmative feedback and others. However, their frequencies of types of peer feedback are significantly different in three aspects, including criticism vs reader friendly, authoritative dialogue vs equal dialogue and static text vs dynamic discourse.