Abstract: Objective:To investigate the clinical significance of vascilogenic mimicry in bi-directional differential malignant tumours. Methods: Three hundred and seventy-seven cases of bi一dlirectional differential malignant tumours, whose clinical and pathological data is adequate, were enrolled into our study. These tumors were divided into two groups, with vasculogenetic mimicry or non-vasculogenetic mimicry. The clinical significance of vasculogenic mimicry was assessed. Results: The prognosis of tumors with vasculogenetic mimicry in melanoma, rhabdomyosarcoma, mesothelial sarcoma except for synovial sarcoma were worse compared to the tumors without vasculogenic mimicry. Conclusion: Tumors with vasculogenic mimicry have a high-grade malignancy, early blood metastasis and poor clinical prognosis.