Objective To observe the effects of β-rays of different degrees of exposure on scars on rabbit ears at different time.Methods 8 square-shaped skin defects.were made on each ear of 20 New Zealand rabbits,with each side of the square being 6mm.The 160 surfaces of wounds on the right ears were used as contrast group.The 160 surfaces of wounds on the left ears were randomly divided into A.B.C.D subgroups with the experimental groups receiving β-ray exposures of 600,1000,1500 and 3000 cGy on the 4th,8th,12th,20th and 28th days.The tissues from the surfaces of wounds in all groups were removed and received detections by photoelectric microscope.Results In the contrast group,blood curst emerged on the 4th day,became stiff on the 8th and came off on the 11th~13th day as the wounds healed.131 scars emerged on the surfaces of wounds one month later.In the experimental groups.No scars appeared in 12 of all surfaces in Group A(30.0%),in 17 in Group B(92.5%),in 22 in Group C(55.5%)or in 27 in Group D(60.0%).The number of fibroblasts in the tissues of scars decreased gradually as more β-ray exposure was given(P0.01).Conclusion Proliferative scars emerge on rabbit ears if no stimulants were given,just as emerge on human body.The inside of rabbit ear can act as a animal model.β-ray application can effectively treat scars,producing a dosageβ-efficiency relationship.