中文摘要：

Appraisal is a major kind of discourse semantic resources construing interpersonal meaning, which includes three subsystems: attitude, engagement and graduation. Engagement resources are linguistic resources of inter- subjective positioning,through which writers or speakers open up or close down dialogic space for putative reader and try to align or disalign readers on the ground of solidarity. This study applies engagement system to analyze political commentaries. It focuses on the denial resources in detail. In political commentaries, by using denial resources, the commentator invokes, and then directly rejects different opinions or beliefs the putative readers may have. Through strategy of dialogic resources, commentators try to make up for disalignments caused by denial and form the grounds for solidarity.