Objective:To explore relationship between anti-cardiolipin antibodies(ACA)-D-Dimer and acute cerebral infarction. Methods:The content of ACA-D-Dimer in blood serum of 187 acute cerebral infarction patients was detected in the morning after fasting over night using ELISA methods, and compared with 135 average healthy cases. Results:The ACA positive rate in acute cerebral infarction group was much higher than control and the difference was statistically significant(P < 0.01); The content of D-Dimer in ACA-positive group was significantly higher than that in ACA-negative group; As the cerebral infarction worsenly, the IgG-ACA positive rate became higher as well as the content of D-Dimer; ACA in the 1st,2nd,3rd and 4th week were compared, suggesting that ACA positive rate reduced as time changed(P < 0.01); ACA positive status was closely related with cerebral infarction patients who were 50 years old or younger. Conclusion:The dynamic changes of ACA-D-Dimer in blood serum might be helpful in predicting prognosis of acute cerebral infarction.