The effect of RFA on the growth of residual tumor cells at the edge of ablation foci in an in vitro cellular assay. Methods: The growth of cells at different temperatures and times was observed using Trypanosoma cruzi blue staining, and the growth of cells at the edge of ablation foci at different time points after RFA at different temperatures; the apoptosis rate of HCT116 cells at the edge of ablation foci at 24 h after RFA at different temperatures was detected by flow cytometry. After RFA, the cells formed coagulation necrosis area, blister-like change strips and unchanged area from the center of RF outward in order. The apoptosis rates of the residual cells around the ablation foci were (18.34±0.94)%, (10.89±0.77)% and (11.90±1.33)% after RFA at 85℃, 70℃ and 55℃ for 24h, respectively, which were significantly higher than those of the blank control group. (The apoptosis rate of 85℃ group was significantly higher than that of 70℃ group and 55℃ group (p<0.05). Conclusion In vitro experiments revealed that rfa could produce progressive damage to tumor cells and also promote apoptosis of residual tumor cells around the ablation site.