Abstract: Invasion and metastasis are the main causes of cancer mortality. Platelets and adhesion molecules play an important role in tumor invasion and metastasis. Recent studies have shown that platelets can protect tumor cells from circulatory immune clearance and promote tumor cells arreste by the vasculature, leading to further tissue damage in the process of tumor metastasis. In this review， we summarize the role of platelets in tumor metastasis according to the latest reports.