Objective To assess the correlation between bispectral index (BIS) and richmond agitation sedation scale (RASS) and sedation-agitation scale (SAS) through the spearman correlation coefficient by systematic review. Methods Databases including PubMed, EMbase, Web of Science, The Cochrane Library (Issue 7, 2016), CNKI, VIP, WanFang Data and CBM were searched from inception to July 2016 to collect literature on the correlation between BIS and RASS and SAS. The studies were screened according to the inclusion and exclusion criteria. After extracting data and assessing the quality of the included studies, meta-analysis was conducted using Comprehensive Meta Analysis 3.0 software. Results A total of 12 studies involving 397 patients were included. BIS was positively correlated with RASS score and SAS, and the summary correlation coefficient was 0.742 with 95% CI 0.678 to 0.795 and 0.605 with 95% CI 0.517 to 0.681, respectively. Conclusion BIS has a good correlation with RASS and SAS, which will provide more options for assessing sedation of patients with mechanical ventilation in ICU.