Objective To establish a syndrome diagnostic criterion for rheumatoid arthritis（ RA） and validate the diagnostic performance of the criteria. Methods We drew up a RA clinical syndrome questionnaire and applied cross-sectional study method. 700 RA patients were surveyed. Then survey information underwent multivariate statistical analysis

including cluster analysis

logistic stepwise regression analysis

stepwise discriminant analysis

principal component analysis

and factor analysis. The diagnostic performance of RA syndrome diagnostic criteria was validated with discriminant analysis. Results Diagnostic indicators of 700 RA patients were reduced from 179 to 124 after first screening; cluster analysis showed that the basic syndromes were damp-heat stagnation

liver-kidney yin deficiency

stagnation of blood stasis

cold-damp stagnation

blood and qi deficiency

phlegm and blood stasis blocking collaterals

and spleen-kidney yang deficiency. By Logistic stepwise regression analysis

the diagnostic indicators of these 7 syndromes were reduced from 124 to 41. Forty six diagnostic indicators were added after stepwise discriminant analysis. Summing up the indicators above

we confirmed that there were 52 sensitive diagnostic indicators for 7 basic syndromes of RA. And after principal component analysis was applied on these 52 indicators

47 remained. Factor analysis then was done on the 47 indicators. According to contributions of the symptoms to the syndrome

syndrome diagnostic criteria of 7 RA basic syndrome types were developed. It is proved with discriminant analysis that the diagnostic accuracy of the criteria was 83. 39%. Conclusion There are 7 basic TCM syndromes in RA

and TCM syndrome diagnostic criteria of RA have a relatively high diagnostic value.