Objective: To investigate whether Shen-Fu Injection(参附注射液, SFI) reduces post-resuscitation immune dysfunction in a porcine model of cardiac arrest by modulating apoptosis of regulatory T lymphocytes(Treg) in the spleen. Methods: After 8-min untreated ventricular fibrillation and 2-min basic life support, 24 pigs were divided into 3 groups with a random number table, i.e. SFI group, epinephrine(EP) group, and saline(SA) group(8 in each group), which received central venous injection of SFI(1.0 m L/kg), EP(0.02 mg/kg) and SA, respectively. The same procedure without CA initiation was achieved in the sham-operated(sham) group(n=6). After successful return of spontaneous circulation(ROSC), apoptosis rate of splenic Treg was detected by flow cytometry; and the m RNA expression of forkhead/winged helix transcription factor(Foxp3) of splenic Treg was detected by real time-polymerase chain reaction; and the levels of interleukin-4(IL-4) and interferon-γ(IFN-γ) in porcine splenic Treg were detected by using enzyme-linked immunosorbent assay(ELISA). Results: Compared with the sham group, the apoptosis rate of Treg was significantly decreased, and the levels of Foxp3 m RNA expression, IFN-γ, IL-4 and IFN-γ/IL-4 were increased in the SA group(P<0.05 or P<0.01). Compared with the EP and SA groups, SFI treatment increased the apoptosis rate of Treg and reduced the levels of Foxp3 m RNA expression, IFN-γ and IFN-γ/IL-4(P<0.05). Conclusions: SFI has significant effects in attenuating post-resuscitation immune dysfunction by modulating apoptosis of Treg in the spleen. Objective: To investigate whether Shen-Fu Injection (SFI) reduces post-resuscitation immune dysfunction in a porcine model of cardiac arrest by modulating apoptosis of regulatory T lymphocytes (Tregs) in the spleen. Methods: After 8-min untreated ventricular fibrillation and 2-min basic life support, 24 pigs were divided into 3 groups with a random number table, ie SFI group, epinephrine (EP) group, and saline (SA) group The same procedure without CA initiation was achieved in the sham-operated sham group (n = 6). After successful return (1.0 mg / kg), EP of spontaneous circulation (ROSC), apoptosis rate of splenic Treg was detected by flow cytometry; and the m RNA expression of forkhead / winged helix transcription factor (Foxp3) of splenic Treg was detected by real time-polymerase chain reaction; and the levels of Interleukin-4 (IL-4) and interferon-γ (IFN-γ) in porcine splenic Tr eg, were detected by using enzyme-linked immunosorbent assay (ELISA). Results: Compared with the sham group, the apoptosis rate of Treg was significantly decreased and the levels of Foxp3 m RNA expression, IFN- γ, IL-4 and IFN- Compared with the EP and SA groups, SFI treatment increased the apoptosis rate of Treg and reduced the levels of Foxp3 m RNA expression, IFN- γ and IFN-γ / IL-4 (P <0.05). Conclusions: SFI has significant effects in attenuating post-resuscitation immune dysfunction by modulating apoptosis of Treg in the spleen.