Objective:To investigate the effect of the expression levels of CXCL12 and CXCR4 of carbon dioxide (CO2) pneu-moperitoneum on nude mice xenografts from human ovarian cancer SKOV3 cells in the same pressure at different times. Methods:A total of 40 animal models of human ovarian cancer SKOV3 cell-bearing nude mice xenografts were established. The animals were ran-domly divided into four groups (n=10), namely, the simple anesthesia group, 0.5 h laparotomy group, and 0.5 and 1 h CO2 pneumoperi-toneum groups. After the aforementioned treatments in the groups, the expression levels of CXCL12 and CXCR4 mRNAs of tumor tis-sues were detected by reverse transcription-polymerase chain reaction (RT-PCR), whereas those of the CXCL12 and CXCR4 proteins were detected by Western blot. Results:The 40 animal models of human ovarian cancer SKOV3 cell-bearing nude mice were success-fully established. After the treatment, RT-PCR results reveal that the CXCL12 mRNA expression was significantly higher in the 1 h CO2 pneumoperitoneum group than that in the other three groups. However, no differences were observed in the CXCR4 mRNA expression of each group. Western blot analysis also obtained the same results. Conclusion:The expression level of CXCL12 in SKOV3 cells of the 1 h CO2 pneumoperitoneum group increased, which possibly promoted the growth of peritoneal tumors, and had a slight effect on tu-mor metastasis.