The key factors of the teaching mode for online-blended learning courses is very important to improve students" online learning ability. Firstly, the study defines the basic characteristics of the blended learning courses, and then proposes the online-blended learning courses, and analyzes the relationship between them; Secondly, based on the teaching practice of online-blended Learning Courses for Engineering Economics and online questionnaire survey for students, the study identify the influencing factors of the teaching mode; Finally, based on the results of questionnaire survey,the key influencing factors of teachers" online teaching, students" online learning and teacher-student interaction are identified. Accordingly, the paper puts forward the strategies to improve the effect of online blended learning courses of Engineering Economics. The research results provide theoretical guidance and practical significance for online blended learning courses based on MOOC or SPOC, and provides a new idea for improvement of blended learning courses and rich practical teaching and learning experience.