In this study, the dynamic expression of granule membrane protein-140 (GMP-140), tissue-type plasminogen activator (t-PA), high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6, matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 was observed in a rat model of myocardial infarction. Out of 276 Wistar rats, 6 were randomly selected as the control group, and the rest were randomly divided into 18 groups, with 15 rats in each group. The left coronary artery was ligated in 9 groups to establish the myocardial infarction model, and the remaining 9 groups served as the sham-operated groups without ligature. Of the surviving rats, 6 were randomly selected from each myocardial infarction group and sham-operated group, respectively, at 6, 12, 18, 24 and 36 h, and at 2, 3, 5 and 7 days after successful modeling. Serum levels of GMP-140, t-PA, hs-CRP, IL-6, MMP-9 and TIMP-1 were then detected using an enzyme-linked immunoassay. The results revealed that, after successful modeling, the serum levels of GMP-140 and MMP-9 continually increased, reaching the first peak at 18 h and the maximum peak on day 2. Levels then decreased slightly, but remained higher than those of the control group (p<0.05). The serum levels of hs-CRP and IL-6 increased, reached a peak at 18 h, and then decreased slightly, but were still significantly higher than those of the control group (p<0.05). The serum level of t-PA decreased significantly (p<0.05) and was restored to baseline by day 5. The serum level of TIMP-1 started to decrease as of 24 h, but was maintained until day 7 (p<0.05). In conclusion, in a rat model of myocardial infarction, the thrombosis, inflammatory reaction and tissue damage-related indicators GMP-140, hs-CRP, IL-6 and MMP-9 increased significantly, while t-PA and TIMP-1 decreased dynamically. Based on the dynamic changes of each indicator, the optimal intervention time may be determined.