Background: Alzheimer's disease (AD), as a chronic neurodegenerative disease, cannot be cured. Thus, it is especially important to achieve” early detection, early diagnosis and early treatment”.Subjective cognitive declin(e SCD) has attracted attention in the field of AD as it can indicate the preclinical stage of AD.The development of simple screening tools can help general practitioners to identify possible preclinical stage of AD, meanwhile reduce the burden on patients and doctors further.Objective: To explore the early simple screening tools for AD by translating English-version SCD questionnaire 9 (SCD-Q9).Methods: The English version of SCD-Q9 was translated into Chinese via “two-person literal translation, back-translation” method of Brislin after obtaining the original author's authorization.Then the original author compared the nuances in language and culture between the Chinese and the original version.The first draft of SCD-Q9 questionnaire was revised and culturally adjusted after the expert panel discussion and pre-survey.From September 6 to 15, 2016, two hundred local residents in ShunYi District were selected by random sampling method.The questionnaire which included general situation and Chinese version SCD-Q9 were used for the investigation.A total of 200 questionnaires were distributed and all of them were effectively recovered, with an effective recovery rate of 100.0%.Project analysis was carried out by using the comparative method between extreme groups (the top 27% of high group and the bottom 27% of low group)of project differentiation degree and the correlation coefficient method of project homogeneity.Cronbach's α coefficient and Spearman-Brown coefficient method were used for reliability analysis.And content validity was analyzed by expert evaluation.KMO test, Bartlett's sphericity test and exploratory factor analysis (EFA)were used for structural validity analysis.Results: The Chinese version of SCD-Q9 contained 2 dimensions and 9 items, including the overall memory function and time comparison (4 items)and daily activity ability (5 items).The subjects were divided into high score group (54 cases)and low score group (54 cases)by item differentiation(top 27% as the high group and bottom 27% as the low group).The differences between the two groups were statistically significant in each item (P<0.05).The correlation analysis of each item and the total score showed that there was a negative correlation between them (P<0.05), the absolute value of the correlation coefficient was >0.400, and all items could be retained.Results of reliability test were showed, the Cronbach's α coefficient of the Chinese version of SCD-Q9 was 0.886.After deleting any item of the questionnaire, the Cronbach's α coefficient ranged from 0.870 to 0.881.With no specific high value, there was no prompt to delete entries.Spearman-Brown's split-half coefficient was 0.892.We also found that the KMO value of the questionnaire was 0.883 and the Bartlett's spherical test χ2 was 1 059.320, df=36, P<0.001, which indicated that the questionnaire was suitable for further factor analysis.Two common factors were extracted by EFA with eigenvalue ≥ 1, and the eigenvalue of common factor 1 was 5.116, whose variance contribution rate was 56.846%, the eigenvalue of factor 2 was 1.231, whose variance contribution value was 13.673%, and the cumulative variance contribution value of two common factors was 70.519%.Conclusion: The internal validity and reliability of the Chinese version of SCD-Q9 questionnaire is good.The development of this questionnaire lays the foundation for its subsequent application in the Chinese population, and provides a simple screening tool for the exploration of SCD. Copyright © 2019 by the Chinese General Practice.