It has been shown that diabetic patients have bone fragility independent of bone mineral density. Recently, diabetes-related bone disease is recognized as one of diabetic complications. It is reported that advanced glycation end products(AGEs)collagen cross-links, low bone turnover with osteoblastic dysfunction, and abnormality of microarchitectures such as cortical porosity and deterioration of trabecular bone structure are involved in diabetes-related bone disease. AGEs and homocysteine directly and negatively affect osteoblasts and osteocytes. Moreover, anti-diabetic drugs also affect bone metabolism. Therefore, the underlying mechanisms are very complex. In this review, we describe the effects of diabetes on bone metabolism based on the recent evidence.