The CLP and CASP model as important research tools have been widely utilized in septic OS. In this study, we compare the oxidative stress condition of CLP and CASP rat models. Compared with sham operation group, infection condition and oxidative stress index were significantly different in CLP and CASP groups. Compared with CLP group, there was no significant difference in natural death rate, bacterial colony positive rate, infection condition, center venous oxygen saturation, and serum levels of TNF-α in the CASP group; whereas, MDA decreased significantly at 72 hours, T-SOD increased considerably at 12 and 72 hours after operation in the CASP group. The serum NO significantly decreased at all time-points except at 12 hours post-operation. Together, our study demonstrated the similarity of oxidative stress condition between CLP and CASP models. However, CASP rats had higher serum NO level than CLP rats.