Abstract: Objective Evaluate the sealing ability of BeeFill -TM- 2in1 hot gutta-percha root canal filling system Methods Fifty freshly extracted singled-root human teeth were prepared with NiTi rotary instruments till they reached uniform standards. The teeth were then randomly divided into 2 groups(n=25): group A:BeeFill -TM- 2in1 hot gutta-percha root canal filling system; group B:cold lateral compaction technique. The simples were immersed in methylene blue dye solution and split longitudinally and the lengths of dye penetration were measured on digital images obtained under microscope at ×20 magnification. Results The average leaked length in group A was （0.78±0.13）m. The average leaked length of group B was（1.96±0.46）mm. There was significant difference between group A and group B (p<0.05). Conclusion BeeFill -TM- 2in1 hot gutta-percha root canal filling system shows better sealing ability compared with cold lateral compaction technique. It is suitable for clinical practice .