An abstract has long been argued as a part of significance in academic writing. Over past decades, ESP researchers have paid mounting attention to abstract writing of research articles. Meanwhile, considerable studies have been conducted to explore its promotional functions. However, studies which investigate both from a microscopic dimension and a macroscopic dimension are rare. To provide a full picture, the current study, based on the Appraisal Theory(Martin & Rose,2003) and genre analysis framework (Santos, 1996),describes the actual promotional function performed in abstracts. 40 abstracts of research articles published in top international journals and written by Chinese scholars were collected. The evaluative stance and rhetorical moves were analyzed. Findings demonstrated similarities and significant differences in the way researchers chose to achieve the promotional purpose. From the microscope, the overall distribution of evaluative expressions, in this paper, tended to be similar across disciplines, while the use of evaluative expressions varied widely within research articles on biology and electric engineering.From the macroscopic perspective, prominence of research results seemed to be common in all selected papers. And abstracts in research articles of linguistics and sociology are more likely to show the move integrity. In-depth investigation shows that promotional features performs differently across disciplines.