Abstract: [Abstract] Objective: To evaluate the effect of skimmed milk and Hank’s Balanced Salt Solution(HBSS) as preservation medium on the root healing and root resorption of the avulsed tooth. Methods: 60 bilateral maxillary first molars was extracted from 30 6-week-old SPF Wistar male rats which were divided randomly into 5 groups (6 each group), and replanted back into the sockets after being placed in HBSS or skimmed milk or in the air ( as negative control) for 30 min right after extraction. The rats were sacrificed on day1,day 3,day7,day14 and day21 after the operation. Then the maxillae were scanned with X-ray and the shadow areas around the mesial roots of maxillary first molars were measured with IPP software. After decalcification, the specimens were made into slices and stained with HE for histological observation. Results: There was no statistically significant difference between milk group and HBSS group regarding the shadow area around mesial roots；the inflammation of root tissue in milk group came to a lighter degree with less resorption, and both the two groups had periodontal healing. Conclusions: Skimmed milk can be recommended as suitable substitute for HBSS and promoted in large-scale.