Objective：To compare the root filling results of 2 thermoplasticized gutta-percha filling techniques （Ultrafil 3D and Obtura Ⅱ ） with cold lateral condensation of gutta-percha. Methods： Sixty freshly extracted maxillary mandibular single- rooted teeth were instrumented and randomly divided into 3 groups： Ultrafil 3D, Obtura Ⅱ and cold lateral condensation groups. The root canal was routinely prepared and the obturation time was recorded. Three days later, 10 teeth of each group were ran- domly stained and the micro effusion length was subsequently measured. The micro-chink between filling materials and the wall of root canal were measured with scanning electron microscope in the other 10 teeth of each group. The data were analyzed using unpaired Student＇s t-test. Results： The longest obturation time was in cold lateral condensation group, then Obtura Ⅱ and Ultrafil 3D group in order, with significant difference found between the cold lateral condensation group and the latter 2 groups （P〈0.01）. The lengths of micro effusion and micro-chink in lateral condensation group were significantly larger than those in the other 2 groups （P〈0.05） ; however, there was no significant difference between the 2 injection thermoplasticized gutta-percha technique groups. Conclusion： Under in vitro condition, the 2 injection thermoplasticized gutta-percha techniques have better adaptation to the canal wall, better root filling results, and less obturation time compared with cold lateral condensation