To improve the basic scientific research ability of the graduate students and ensure the quality of the dissertation, this paper clarifies the connotation and extension of the scientific research ability from the perspective of universities and tutors. The scientific research ability of graduate students includes two aspects, which are subjective aspect and objective aspect. The subjective initiative of graduate student has an important impact on graduate students" achievement level through objective aspect, such as scientific literacy and scientific research methods. Thesis proposal, mid-term examination and thesis are the three key nodes of graduate research. It is an important guarantee for the research level of graduate thesis to effectively complete the work required by these key nodes.