Abstract: Power trio provides important linguistic resources for meaning construction and knowledge accumulation. This paper analyses the features of power trio in popular science texts, social texts and literary texts in a College English Textbook. The results shows that in the popular science texts, the three power resources interact with each other to form the periodicity of semantic waves; in the social texts, the semantic density is weaker, and information flow is less regular than that in the popular science texts; and power trio features in the literary texts are not evidently displayed due to its specific narration method. These findings can help college English teachers to get a better understanding of the knowledge codes in different fields and further improve the quality of College English teaching.