Objective. The present study aimed to elucidating the correlation of apolipoprotein（a）[apo（a）] with cerebral infarction at the levels of molecule and protein. Methods. The serum Lp（a） level

by means of ELISA

the polymorphism of apo（a） protein

by SDS PAGE/Western blotting combined with silver staining assays

and the sequence polymorphisms in 5’ control region

the first exon and intron of apo（a）gene

by PCR SSCP/AFLP assays

were detected in 85 healthy controls and 42 cases of cortical cerebral infarction. Results. The serum Lp（a） level was markedly higher in the patients（152.59±3.41 mg/L）than that in the controls（56.21±3.67 mg/L）（t=4.15

P<0.001）

even between the subjects with the same apo（a） phenotype. The frequency of low molecular weight phenotype was significantly higher in the patients than that in the controls（0.5238 vs. 0.2941）. There were 2 sites of sequence variance in the 5’ control region of apo（a） gene in our studied population

which were of significant difference between patients and controls

and were related to the variation of serum Lp（a） level. Conclusion. Our study found that the low molecular weight phenotype of apo（a） was closely associated with cerebral infarction

suggested that the variation of serum Lp（a） level be determined by not only the size of apo（a） gene but also its sequence

which indicated that both the size and sequence of apo（a） are associated with the susceptibility to cerebral infarction.