Objectives: Osteoporosis is a disease described by a skeletal degradation of bone tissue domination to increase risk of fracture. Traditionally, Rusa unicolor antler from East Kalimantan is used to treat many kinds of diseases, and one of them is disease related to bone turnover. The present research aims to analyze the effects of 70% ethanol and aqueous extracts of Rusa unicolor antler from East Kalimantan on nitric oxide inhibition, osteoblast differentiation, and mineralization related to bone turnover. Materials and methods: The nitric oxide inhibition of the extracts in LPS-stimulated RAW 264.7 cells were evaluated by Griess reagent while osteoblast differentiations of extracts were evaluated by measuring alkaline phosphatase in p-nitrophenyl phosphate and their mineralization was determined using Alizarin Red Staining method. Results: The 70% ethanol and aqueous extracts inhibited cells inflammation (40% and 80%) and stimulated osteoblast differentiation (65% and 52%), respectively. In mineralization test, the aqueous extract showed two times higher effect than that of 70% ethanol extract. u n c o r r e c t e d p r o o f Conclusion: The extracts can be considered to successfully reduce expression of inflammatory markers on osteoblasts and maintain osteoblast functions.