Objective To evaluate the security of tirofiban and its effects on subacute thrombosis after implantion of drug-eluting stents (DES) in complex coronary lesions. Methods A cohort of consecutive complex coronary heart disease (CHD) patients,who received implantation of DES from Jan,2005 to Dec,2008,were analyzed retrospectively. Totally 289 patients were divided into two different stages according to frequency of tirofiban use. There were 171 patients with less frequency of tirofiban use during the first stage,and 118 patients with more frequency of tirofiban use during the second stage. The clinical features,coronary artery lesions,DES implantation,frequency of tirofiban use,bleeding complication,and occurrence of subacute thrombosis in patients at two stages were recorded respectively. The security of tirofiban and its effects on subacute thrombosis after DES implantation were analyzed. Results There was no statistical difference in patients’ clinical data between two stages. Patients with coronary lesions of type B2 and type C were 108 and 63 in first stage and 78 and 40 in second stage respectively (P>0.05). There was no statistical difference in total length and number of implanted stents between two stages(34.4±14.3) mm vs (36.5±16.3) mm,(3.1±1.3) vs (2.9±1.2),P>0.05. Compared with the first stage,there were more patients who used tirofiban in the second stage (15.2% vs 62.7%,P<0.01). The occurrence of bleeding complication between two stages was not statistically different (4.67% vs 4.23%,P>0.05). There was no statistical difference in the occurrence of subacute thrombosis between two stages,which was 0% and 1.75% respectively,but there was a decreasing tendency with more frequent use of tirofiban. Conclusion It is safe to use tirofiban after the implantation of drug-eluting stents in complex coronary lesions. It may also have the tendency to reduce the occurrence of subacute thrombosis.