Abstract: Objective: The aim is to investigate the effect of PARP inhibitor 5-AIQ on PARP/NF-κBp65 complex and the NF-κB activity in murine colon carcinoma CT26 cell lines．Methods: The murine colon carcinoma CT26 cell lines were treated with 5-AIQ in vitro．The expressions of PARP and NF-κBp65 were analyzed by Western Blot. The PARP/NF-κBp65 complex was analyzed by co-immunoprecipitation. The NF-κB binding activity was detected by electrophoretic mobility shift assay (EMSA). Results: Compared with 5-AIQ-untreated group, the expressions of PARP and NF-κBp65 were markedly decreased in 5-AIQ-treated colon carcinoma CT26 cell groups (P<0.05). The PARP/NF-κBp65 complex was decreased in 5-AIQ-treated colon carcinoma CT26 cell group (P<0.05).The NF-κB DNA binding activity was also reduced in 5-AIQ-treated colon carcinoma CT26 cell groups(P<0.05). Conclusions：These results suggest that 5-AIQ can inhibit PARP expression in murine colon carcinoma CT26 cells, and further inhibit the formation of PARP/NF-κBp65 complex and NF-κB activity.