Abstract: The relationship between the subjective cognitive decline and the incidence of dementia is found in existing researches. According to the related researches, subjective cognitive decline is the outcome of subjective assessment without abnormalities in objective neuropsychological assessment, which could be the earliest discernible sign of Alzheimer. It could be influenced by demographic characteristic, personality and mood status. The prognosis can be predicted by biomarker, mood status. In this field, the conceptual framework and the relationship with dementia need to be further clarified, and the results of related studies provide a new perspective for the prevention and diagnosis of dementia, and can provide reference to nursing intervention.