Abstract:Abstract: Through the modified Toulmin argument model, the paper explores the English majors’ logical thinking quality in argumentative writings from a rhetorical perspective. It means to investigate: (1) the argumentative structure to show the completeness of logical process, (2) the objectiveness of the reasoning reflected in the probability of the claims, (3) the power of reasoning reflected in the awareness of the possible opponents; (4) the broadness and the depth of thinking. The results are: (1) 92% of the subjects use some type of argumentative structure as their discourse pattern; (2) 95% of the subjects use extreme form of modal qualifier, which greatly hurts the objectiveness of arguments; (3) most subjects lack opponent awareness, and only 29% use rebuttal potential, however, without any real countering, which affects the power of their arguments; (4) there is not salient improvement of the broadness and depth of thinking in different grades.