Aim To study the relation between apolipoprotein E polymorphism and myocardial infarction. Methods 110 patients with myocardial infarction and 131 normals were enrolled and blood samples were collected. Their apoE genotyping were performed by polymerase chain reaction (PCR). Results Both in cases and controls, the allelic frequency of E3/3 was highest, reaching 70.1 percentage of whole volume, hemozygote of apo E3 was moderate, and homozygote E4/4 was lowest. The frequencies of E3/4 and E4/4 was significantly high in patients with myocardial infarction compared with controls (P<0.01). It was found primarily that the age of first acute myocardial infarction was earlier in the carriers of E4. Conclusions apo E4 is an important genetic mark of the patients with myocardial infaction. The age of first acute myocardial infarction was earlier in the carriers of E4.