Objective To explore the features of rheumatoid arthritis（ RA） onset. Methods Totally 188 RA patients were selected and a 12-month investigation was made. Two weeks were taken as one observation point and 24 observation points were set up. The C-reactive protein（ CRP） was detected at each observation point. The tender joint count（ TJC28） and swollen joint count（ SJC28） was observed for calculating disease activity score of 28 joints（ DAS28）. At the same time

patients were classified according to TCM syndromes. The meteorological data were collected. The correlation between meteorological factors（ temperature

air pressure

relative humidity and wind speed）and DAS28 was analyzed by bivariate linear correlation analysis. Results In 188 RA patients

the most common TCM syndrome was blockage of cold and damp（ 71 cases

37. 8%） and it occurred mainly in winter. There is a statistical significance in syndrome distribution difference between each season（ P < 0. 05）. Among meteorological factors

temperature and wind speed had negative correlation with DAS28（ P < 0. 01）. Conclusion Blockage of cold and damp is the main syndrome of RA which mainly occurs in winter. When temperature and wind speed go down

disease activity of RA will go up on the contrary.