Objective To explore the expression of platelet-derived growth factor CC (PDGF-CC) during intravenous thrombolysis in rats and the significance thereof. Methods The inferior vena cava thrombosis model was established in adult male SD rat, and control and experimental groups were set up. Specimens of inferior vena cava and thrombus therein (n=12) were collected on day 1, 3, 7, 14, 21 and 28 after modelling. The expression of PDGF-CC protein and mRNA in inferior vena cava and thrombus during thrombolysis was determined by Western blotting and real-time qPCR. The specimens of inferior vena cava and thrombi (n=3) of rats 7 days after modelling were collected to observe the pathohistological and immunohistochemical changes. Results Western blotting and real-time qPCR showed that PDGF-CC protein and mRNA were expressed in inferior vena cava thrombi from 1 to 28 days after modelling, and the peak value of expression was found on day 7(P<0.05). PDGF-CC protein and mRNA were also expressed in the wall of inferior vena cava, but the expression level was low and no significant difference was found between groups (P>0.05). Immunohistochemical analysis revealed that the specific expression of PDGF-CC was present surrounding the new vessels in thrombi 7 days after modelling. Conclusions PDGF-CC has been found to express in high level during intravenous thrombolysis in rats, and it specifically expresses around the new vessels in thrombi, implying that PDGF-CC may play an important role during intravenous thrombolysis.