Abstract: [Abstract] Objective To study the effect of low bone metabolic rate on the feasibility and stability of immediate loading micro-implant anchorage, the experiment was conducted. Methods 20 healthy female Wistar rats were randomly divided into two groups, namely hypothyroid group and control group. Each group has 10 rats. 1ml/100g 0.1% propylthiouracil was instilled to each rats of hypothyroid group according to their body weight for 28 days. The rats in control group were stilled distilled water in the same manner. After that the venous blood from inner canthus was collected and T3, T4, TSH were detected by radioimmunoassay. Then micro-screws were implanted and 100g force was loaded to all rats for after 28 days. Tetracycline and calcein was marked to the rats after loaded 16 days and 24 days, respectively. All rats were killed after loaded 30 days. The mobile space was measured by X-ray. Super-hard nail tissue sections containing plant was observed under fluorescence microscopy and light microscopy. The bone mineral deposition rate and bone contact ratio was calculated. Results It showed that the level of T3 and T4 in hypothyroid group was lower than that of in control grou, but the level of TSH was contrary. The mobile space, bone mineral deposition rate and bone contact rate were lower in low bone metabolism group than those of in control group. Conclusion Immediate loading micro-implant anchorage has feasibility and validity.