[Abstract] Background Mild cognitive impairment (MCI)is a syndrome defined as cognitive decline greater than expected for an individual’s age and education level but that does not interfere notably with activities of daily life. MCI has a high risk of developing into dementia. Objective Preoperative evaluation for high-risk patients is conductive to the implementation of the “precision anesthesia”. In other words, with proper anesthetic medicine and method , the progression of MCI can be controlled or even delayed. Content In order to provide evidence for rational clinical application, the author comprehensively reviewed the screening scales of MCI home and abroad. Trend Although the application of Montreal cognitive assessment (MoCA)on poorly educated patients has drawbacks, this screening scale is still the best single scale for preoperative evaluation so far. In addition, the application of the Montreal cognitive assessment-basic(MoCA-B) and Mini-mental status examination (MMSE)combined with other scales will provide new thoughts foraccurate assessment of the cognitive function of the MCI patients.