Varied TCM constitutions in the patient of acute cerebral infarction were classifyed by using HLA - DQAl allehc gene to analyze hereditary susceptibility of constitution types and relation among constitution

syndrome and treatment. PCR-SSP technique was used for classification of Yin - deficiency Yang - deficiency

Qi - deficiency

phlegm - dampness and blood stasis constitution in 103 cases of acute cerebral infarction and HLA - DQAl allelic gene was used for gent classification in 99 cases of nomal constituion. Results indicated that HLA -DQA * 0501 gene type in Yin -deficiency constitution was significant higher than that of normal constitution CP<0. 01) : HLA -DQAl * 0301 gene type in Qi - deficiency

phlegm - dampness and blood stasis constitution all was higher than normal constitution （P <-0. 01）. It is suggested that HLA - DQAl * 0501 gene is correlated with Yin - deficiency in the patient of acute cerebral infarction. Thus

genetical background of relation of constitution with syndrome

and constitution with " treating the same disease with different methods" are explained from view of point of molecular biology.