Abstract: Objective:To demonstrate the feasibility of the osteosarcoma devitalization method by vacuum dehydration at room tem -perature. Methods:For the in vivo study, the VX 2 tumor mass was treated by vacuum dehydration, rehydrated in ice water, and im -planted in the rabbit to determine the safety time to deactivate the tumor. For the in vitro study, the osteosarcoma mass was devital-ized by vacuum dehydration, and the dehydration rate and ATPase activity were determined. Histopathological changes in the tumor were also observed. The change in the biomechanical strength of rabbit bone and tendon after vacuum devitalization treatment was detected. Results:At room temperature, the safety time to deactivate the VX 2 tumor was 60min, and the dehydration rate was93. 8% at this time point. After vacuum dehydration, the tumor mass evidently shrunk, presenting a porous structure. The osteosarcoma cell became small, and cell structure damage was observed under light microscope. Disrupted cell membrane and organelles were seen un-der transmission electron microscope as well as broken down chromosomes. The activity of ATPase was evidently lower than in the control group. The strength of bone and tendon did not decrease significantly after vacuum dehydration. Conclusion: Treatment by vacuum dehydration at room temperature for 60min does not result in differences of the bone and tendon strength. However, it can inactivate both soft tissue and bone tumor mass completely.