To establish an animal model of benign lymphangiomas of C57BL/6 mouse in vitro and to observe the effect of mouse ascites melanoma cell B16-F1 on the lymphangiogenesis, 16 C57BL/6 mice aged 8 weeks were given two intraperitoneal injections of incomplete Freund's adjuvant at a15-day interval. The induced neoplasms were studied histopathologically and thhe neoplasms speci- mens were immunohistochemically examined for the expressions of VEGF-C (vascular endothelial growth factor-C) and Fit-4 (VEGFR-3, vascular endothelial growth factor receptor-3). The neoplasms were harvested and embedded in fibrin gel for culture in conditioned medium of B16-F1 cells in vitro and observed under inverted microscope. Our results showed that white solid tumor masses devel- oped in peritoneal cavity after the induction. The tumors were confirmed to be lymphangioma by gross and histological examination. The tumor cells expressed both VEGF-C and Flt-4. Lymphatic capillaries coming from lymphangioma specimen grew into the gel and the conditioned medium of B16-F1 cells was found to be able to promote the growth of the vessels. It is concluded that intrap- eritoneal injection of incomplete Freund's adjuvant is a good method for inducing benign lymphan- giomas in mouse and B16-F1 cells can promote lymphangiogenesis.