Induction of micro-current in subject is known to be effective on the treatment of inflammatory disease. Thus, this study evaluated that the micro-current electrical treatment (MET) can reduce rheumatoid arthritis (RA), which is one of inflammatory disease, and tried to find optimized level of current for treatment. 55 male 11-week-old C57BL/6 mice were used and randomly allocated into five groups; normal group (N; n=11), the group of induced RA (C; n=11) and three groups of induced RA with MET (M) using different levels of current by 22 μA, 50 μA, and 400 μA (22M, 50M and 400M; n=11, respectively). MET was carried out for 1 hour each day. Both 3rd metatarsal (3rd MT) and tarsal (T) were scanned by in-vivo micro computed tomography (micro-CT) at 0week and after 3weeks in order to obtain structural parameters including BMD (Bone mineral density), BV (Bone volume) and Obj.N (Mean number of objects per slice). In M groups, all the measured parameters after 3 weeks were significantly higher than those of C group regardless of the current levels. However, there is no significant difference among the different levels of electrical current at 3week. These results indicated that the MET may be effective on the treatment of RA. However, we cannot assure the optimized level of current to treat RA tremendously.