Periodontitis is a worldwide disease that is caused by bacterial infection and inflammation, which damage both soft and hard tissue. Previously, diagnosis was given after the periodontal examination plus radiological examination, but recent research has found the importance of fluid peptides in the diagnosis, prognosis and management of the disease. There are some new techniques applied to this principle, such as POC, personalized medicine, and proteomic analysis. But there are still some challenges that should be overcame.