Abstract: Objective 　To observe the effect s of heparin on mouse hepatocarcinoma cell line Hca-F and Hca-P's adhesion in vitro and the lymphogenous metastasis in vivo. In order to detect how heparin plays its role. Methods 　Using Stamper-Woodruff method, cell chemistry and flow cytometry analysis to detect the effects of heparin in different concentrations. Results 　Heparin can inhibit obviously the adhesion between Hca-F and Hca-P cells and ice frozen sections of mouse lymph nodes in vitro, compared with saline-treatment group ( P < 0. 01) ; heparin can inhibit the lymphogenous metastasis of Hca-F cells in vivo, which has statistical significance between 100 U heparin group and saline-t reatment group ( P < 0. 05) . Conclusion 　Both Hca-F and Hca-P cells have the expression of L-selectin, but their expression level is different . The expression level of L-selectin on mouse hepatocarcinoma cell line Hca2F and Hca2P is positively related to the lymph node metastasis potential. Interaction between L-selectin and its ligand is inhibited partially by heparin. Therefore heparin have the competence of inhibiting tumor cell′s lymphogenous metastasis. Meanwhile, it also demonst rates that L-selectin can facilitate metastasis of Hca-F and Hca-P cells to the lymph node.