Abstract: Objective To compare a new level of consciousness monitor, called the index of consciousness (IOC) with the bispectral index (BIS) during propofol target-controlled infusion (TCI) anaesthesia induction. Methods After ethical committee approval and written patient consent, data from 30 patients were recorded. All patients were induced with propofol target-controlled infusion (TCI), until the Observer’s Assessment of Alertness and Sedation (OAAS) scale level 1 was reached, and then IOC and BIS were calculated during OAAS 5~1. Results IOC (0.988, P<0.001) and BIS (0.986, P<0.001) positively correlated with OAAS, while IOC positively correlated with BIS (0.997, P<0.001). Conclusions IOC has the good correlation with BIS during propofol target-controlled infusion (TCI) anaesthesia induction.