Objective To explore the relevance between Chinese medicine syndromes and constitution types in patients with influenza A. Methods Totally 151 confirmed cases of influenza A were collected. Chinese medicine syndromes information was investigation by physicians with the four diagnosis methods

and data on constitution types were gathered by a questionnaire survey. Then Chinese medicine syndromes were analyzed and constitution types were identified. The syndromes were took as dependent variable and 9 types of constitution as independent variable

multivariate linear regression analysis was conducted. Results Among 151 patients

there were 136 cases with Wei-fen syndrome（ 90. 1%）

91 cases with Qi-fen syndrome（ 60. 3%）

but no any cases with Ying-fen syndrome and Xue-fen syndrome. Among patients with Qi-fen syndrome

there were 52 cases with Yangming syndrome（ 34. 4%）

30 cases with lung-heat syndrome（ 19. 9%）

40 cases with Shaoyang syndrome（ 26. 5%）

10 cases with chestdiaphragm syndrome（ 6. 6%）

and 28 cases with damp obstruction syndrome（ 18. 5%）. The distribution of different constitution types in 151 cases in a descending order was that the most common one was phlegm-dampness constitution

followed by dampness-heat constitution

Qi deficiency constitution

Yang deficiency constitution

Qi stagnation constitution

Yin deficiency constitution

blood stasis constitution

normal constitution

and specific diathesis constitution. Regression analysis demonstrated that there was a negative correlation between influenza A with Qi-fen syndrome and normal

or specific diathesis constitution

and a positive correlation between influenza A with Qi-fen syndrome and Yin deficiency constitution. There was a positive correlation between Yangming syndrome and Yin deficiency constitution

a positive correlation between Shaoyang syndrome and Qi stagnation constitution

a positive correlation between lung heat syndrome and phlegm-dampness constitution

a positive correlation between damp obstruction syndrome and phlegm-dampness constitution

a negative correlation between damp obstruction syndrome and specific diathesis constitution

a positive correlation between disease involving Wei-fen and Qi-fen syndrome and Yin deficiency constitution

a negative correlation between disease involving Wei-fen and Qi-fen syndrome and specific diathesis constitution

a positive correlation between Wei-fen syndrome alone and normal

or specific diathesis constitution

and a negative correlation between Wei-fen syndrome alone and Yin deficiency constitution（ P < 0. 05）. Conclusion Yin deficiency

phlegm-dampness

Qi stagnation

normal

and specific diathesis constitutions were 5 main constitution types influencing Chinese medicine syndromes in influenza A patients. There was a close relationship between Chinese medicine syndromes at onset and patients’ constitutions.