Objective To explore the characteristics of traditional Chinese medicine（TCM） syndromes and its correlation with TCM constitutions in patients with ischemic stroke（IS）. Methods A multi-center

prospective registration study was conducted; data on IS patients from seven centers across the country from July 2016 to November 2019 were collected

including gender

age

body mass index（BMI）

basic disease

course of disease and other general information

as well as diagnosis information

disease situation and other clinical data. Systematically trained clinicians of each participating center determined the TCM syndrome and constitution of each patient. TCM syndromes of IS patients were classified into seven major types

which were wind-phlegm fire hyperactivity syndrome

wind-fire harassing the upper body syndrome

phlegm-heat and bowel excess syndrome

yin deficiency and stirring of wind syndrome

wind-phlegm stasis and constraint syndrome

phlegm-damp confusing the mind syndrome

qi deficiency and blood stasis syndrome. Nine constitution types were involved

including yang deficiency constitution

yin deficiency constitution

qi deficiency constitution

phlegm-damp constitution

damp-heat constitution

blood stasis constitution

qi constraint constitution

inherited special constitution and balanced constitution. The canonical correlation analysis was performed to analyze the correlation between TCM syndromes and constitutions. Results A total of 2558 patients were included

who were mainly of qi deficiency and blood stasis syndrome（1

506 cases

58.87%） and wind-phlegm stasis and constraint syndrome（1

166 cases

45.58%）; the major constitutions were balanced constitution（632 cases

24.71%）

qi deficiency constitution（561 cases

21.93%）

blood stasis constitution（531 cases

20.76%）

and phlegm-damp constitution（370 cases

14.46%）. Correlation analysis showed that qi deficiency and blood stasis syndrome was significantly correlated to constitutions of qi deficiency

blood stasis and yang deficiency; the wind-phlegm stasis and constraint syndrome was significantly correlated to phlegm-damp constitution and yang deficiency constitution; wind-fire harassing the upper body syndrome and yin deficiency and stirring of wind syndrome were correlated to yin deficiency constitution; significant correlations were also found between wind-phlegm fire hyperactivity syndrome

phlegm-damp confusing the mind syndrome and phlegm-damp constitution

as well as between wind-fire harassing the upper body syndrome

phlegm-heat and bowel excess syndrome

and damp-heat constitution（P<0.05 or P<0.01）. Conclusion The common syndrome types of IS patients are qi deficiency and blood stasis syndrome and wind-phlegm stasis and constraint syndrome; the common constitution types include balanced constitution

qi deficiency constitution

blood stasis constitution and phlegm-damp constitution; moreover

the TCM syndromes are significantly correlated to the constitutions.