The feasibility and validity of skull tissue ablation with pulse CO2 and Er:YAG lasers were evaluated. Healthy male New Zealand rabbits in vivo were used in the experiment. Skull tissue of animal model was completely exposed by surgeon with conventional methods,and then put on a PC-controlled motorized linear drive stage and moved repeatedly through the focused beam of both lasers with certain work distance and moving rate until an about 3 cm length ablation groove was obtained. Diamond drill was used as control group. The appearance and morphological changes of ablation groove were observed by naked eye and microscope. Following traditional histological process,the micrographs of ablation groove′s cross-section slices were obtained,and its geometry and thermal injury thickness were measured. The ablation rate and ablation efficiency for both lasers were also compared. It shows that both lasers can be used for bone hard tissue ablation and similar outcomes as diamond drill were obtained. Pulse CO2 laser presents high ablation rate with strong thermal damage,while Er:YAG laser shows better outcomes compared with CO2 laser with higher ablation efficiency and smaller thermal injury. Furthermore,light absorption by blood during operation will reduce ablation efficiency and increase thermal injury which should be controlled efficiently in clinical application.