Combining elements of online and face-to-face education, blended learning is emerging as an important teaching and learning model in higher education. In order to examine the effectiveness of blended learning, as compared to the traditional face-to-face learning mode, this research investigated the learning outcomes of students following English as a Second Language (ESL) course under the two learning modes in a comprehensive university in Beijing, China. A large database was analyzed including student variables (gender, grade and knowledge domain), the different learning modes, and student performance in this study (N = 5376). The results show that students following blended learning had better academic achievements in their ESL courses compared to students following the traditional face-to-face learning mode. Student factors (gender, grade, knowledge domain and pre-test) were taken as covariates in order to assess the differences of student performance (dependent variable) in blended learning and traditional face-to-face learning.