There are a variety of methods to reconstruct the mucosal defect after the ablation of buccal cancer. We used the radial forearm free flap (RFFF), pedicled buccal fat pad flap (PBFPF) or split-thickness skin graft (STSG) to reconstruct the buccal mucosal defect in our series respectively and compared the mouth-open width among these methods. We found there was no significant difference in the change of mouth-open width between the Group STSG and Group PBFPF. However, the negative effect on the mouth opening was significantly less (p<0.05) in Group RFFF when compared with the Group STSG or Group PBFPF. In conclusion, reconstruction with radial forearm free flap for buccal mucosal defect carries more chances to preserve the original mouth-open width than with pedicled buccal fat pad flap or split-thickness skin graft among the selected patients who undergo tumor resection for T2 or T3 buccal cancer.