ObjectiveTo summarize and analyze the relevant studies about the tumor suppressor phosphatase and tensin homolog deleted on chromosome ten (PTEN) and thyroid tumor then further elucidate?the possible mechanism of thyroid tumor formation and progression. Mothods Domestic and international literatures investigating the correlation between PTEN and thyroid tumor were retrieved and reviewed. ResultsThe abnormal expression of PTEN protein resulted by the mutation or methylation of PTEN gene may up-regulate the expression of its downstream effectors such as PI3K, mTOR, FAK, etc. This probably correlate with thyroid neoplasia and progression. Conciusions Abnormalites of PTEN and its downstream signal ways may correlate with the initiation and development of thyroid tumors. However, the specific mechanism still remains unclear and need more further researches