Objective To observe the changes of serum levels of inflammatory cytokines in the elder patients with clopidogrel resistance (CLR) after coronary stenting. Methods A total of 93 patients with unstable angina pectoris received coronary stenting were enrolled, and peripheral blood samples were taken before and 24 hours, 1 week and 1 month after surgery. The platelet aggregation (PAG) induced by adenosine diphosphate (ADP) were detected, and all patients were divided into CLR group (n=33) and normal response group (n=60) according to PAG response. At the same time, the levels of C-reactive protein (CRP), soluble fragment of CD40 ligand (sCD40L) and P-selectin were detected by enzyme-linked immunosorbent assay. Results The incidences of CLR were 35. 5% (33/93), 26. 9%(25/93) and 20. 4%(19/93) respectively 24 hours, 1 week and 1 month after surgery. The levels of CRP C(8. 8 ± 2. 5) mg/L at 24 hours, (5. 3 ± 2. 5) mg/L at 1 week], P-selectin [(73. 8±34)×10~(-3) ng/L at 24 hours, (70. 5±31. 6)×10~(-3) ng/L at 1 week, (66. 4±22. 3) ×10~(-3) ng/L at 1 month] and sCD40L C(7. 7 ±2. 3)×10~(-3) ng/L at 24 hours] after surgery in CLR group showed significant differences comparing with pre-surgery and normal response group (all P< 0.05). The CLR at 30 days after coronary stenting was significantly correlated with the level of P-selectin (r=1.334) and smoking (r= 1.053). Conclusions The levels of CRP, P-selectin and sCD40L in some elder patients after coronary stenting are increased and may be correlated with CLR. The levels of P-selectin and smoking are the predictors for CLR.