In recent years, people all over the world have suffered from various diseases such as cancer, myocardial infarction, osteoporosis, hypertension, and diabetes mellitus (DM). Especially, DM, well-known as one of lifestyle-related diseases, has been regarded as a serious problem, because it is difficult to fully recover. The number of patients suffering from DM in 2007 was reported to be approximately 200 million people worldwide. However, insulin preparations and synthetic therapeutics, which are clinically used treatment of DM, have been associated with problems such as physical and mental pain due to daily injections and certain severe side effects, respectively. Zn, which is an essential trace element in animals and humans and plays an important role in maintenance of their lives, has been indicated to exhibit insulin-like activity. Since the finding of insulin-like effects of Zn, several Zn complexes have been proposed as a new type of anti-diabetic therapeutics which is differ from existing medicines. In this symposium, we introduce the anti-diabetic effect, complication relieving effect, and action mechanism of bis(2-mercaptopyridine-N-oxidato)Zn complex with Zn(S(2)O(2)) coordination mode.