This study constructs a dynamic assessment model of academic English ability for Chinese science and engineering majors under U-learning environment.Based on literature review of ubiquitous learning and dynamic assessment,the model focuses on the cultivation of students' academic English awareness and integrates an in-class with off-class interventionist session so as to enhance students' academic English proficiency.To illustrate the application of this model,a writing assessment model and an oral assessment model are designed to meet the demands of Academic English Reading & Writing Course and Academic English Listening & Speaking Course in University of Shanghai for Science and Technology.