Diabetes, characterized with hyperglycemia, may lead to many complications, such as ketoacidosis, hypertension, atherosclerosis, eye diseases, diabetic nephropathy. Diabetes is one of the factors which are responsible for periodontal disease, and this opinion has been approved by many researchers. However, there is still dissension when it comes to the relationship between diabetes and caries. Majority of researchers consider that diabetes may lead to high caries prevalence, but there is still opposite point. In our article, we expatiated the new development about the relationship between diabetes and caries.