Abstract: Objective :To analyze and explore the effect of flow and the diameter of liver artery onCryoablation of malignant liver tumors. Methods : adult experimental dogs were randomly divided intotwo groups, with each of six. The experimental group were underwent liver artery obstruction andcryoablation whereas the control group with only cryoablation. Every dog had two cryoablation cites ofnear and far away the entry of liver artery. Animals were sacrificed immediately or 7d and 14d after thetreatment. General changement of the liver were observed and the extent of cryoablation were measured.Pathological examination of the target and surrounding area have been done. Results :(1)At the sametime point and same cryoablation site, experimental group had a lower temperature than the contralgroup; target temperature near the entry of the liver artery was higher in each group at the same timepoint. (2) The diameter of the cryoablation range near the entry of the liver artery was longer than thatof far away in each group, and the diameter of experimental group was longer than the contral group.(3)In experimental group, the necrosis was more thorough and the duration time was longer than the con-trol group. The vessel damages of as little as 1mm around the target area was observed even after 14days of cryoablation. Conclusion :Liver artery flow and the diameter of the vessels are the importantfactors of the efficiency in cryoablation.