Obestatin was a newly found ghrelin-associated peptide(GAP), which could be bound to the orphan G protein-coupled receptor GPR39. Obestatin suppressed food intake, inhibited gastrointestinal function, and decreased body-weight gain which was regarded as the biological equally matched material or Yin and Yang activated polypeptide. However, recent reports indicated that obestatin could not specifically bind to GRP39 receptor, and could not alter ghrelin-induced biological functions. According to the reports above, researches related to obestatin and GPR39 were reviewed in the article.