Currently, the incidence of colorectal cancer is increasing year by year, and the mortality rate also ranks among the front of malignant tumors. The proportion of rectal cancer is also increasing year by year, and most of them are locally advanced rectal cancer(LARC) with extremely poor prognosis. Preoperative neoadjuvant therapy for LARC has been widely recognized in clinical practice, and how to accurately predict the efficacy of neoadjuvant therapy has been a hot spot of scholars' attention. In recent years, many scholars have explored that some blood biomarkers have good predictive ability for the efficacy of neoadjuvant therapy. Reviewing the studies in the field of rectal cancer, these blood biomarkers can be broadly divided into three directions: inflammation-related biomarkers, nutrition-related biomarkers, and intestine-specific tumor markers. For these biomarkers, different scholars have adopted different time points for sampling, mainly including before, during and after neoadjuvant therapy. In this paper, we review and summarize the research progress of these blood biomarkers in the neoadjuvant treatment of rectal cancer based on previous studies.