Abstract： Objective:To explore the association of the impaired cognition and the deposition of β-amyloid (Aβ) in normal cognitive (NC) and mild cognitive impairment (MCI).Methods:From December 2018 to January 2021, 305 subjects (113 males, 192 females; age (64.0±7.7) years) who completed neuropsychological tests and MRI in Shanghai Sixth People′s Hospital, Shanghai Jiao Tong University and 18F-florbetapir (AV45) PET imaging in Huashan Hospital, Fudan University were retrospectively analyzed. The subjects were divided into MCI group and NC group based on neuropsychological tests, and each group was further divided into Aβ-positive and Aβ-negative based on PET imaging results. Independent-sample t test, Mann-Whitney U test and χ2 test were used to analyze the data. Results:There were 118 subjects in MCI group and 187 subjects in NC group. The Aβ-positive rate in MCI group (37.3%, 44/118) was higher than that in NC group (26.2%, 49/187; χ2=4.19, P=0.041). The assessment performances of MCI group in general cognitive function, memory function, language function and executive function were inferior to those of NC group ( t values: from -10.63 to -6.31, z values: from -11.01 to -6.03, all P<0.001). The Auditory Verbal Learning Test-Long Delay Recall (AVLT-LDR) score of Aβ-positive subjects was lower than that of Aβ-negative subjects in MCI group (1.00(0.00, 3.00) and 3.00(1.00, 4.00); z=-2.49, P=0.013). The Montreal Cognitive Assessment Basic (MoCA-B) score of Aβ-positive subjects was lower than that of Aβ-negative subjects in NC group (25.29±2.67 and 26.36±2.42; t=-2.61, P=0.010). Conclusion:Compared to Aβ-negative subjects, MCI patients with Aβ-positive perform worse on memory tests, and NC subjects with Aβ-positive perform worse on general cognitive function.