Abstract: Objective To investigate the effect of urokinase-type plasminogen activator receptor (uPAR) on the invasion and metastasis in vitro and in vivo of hepatoma SMMC-7721 cell line. Methods Fluorescence-activated cell sorter (FACS) was used to sort uPAR positive cells (uPAR+ group) and uPAR negative cells (uPAR- group) from SMMC-7721 cell line,the invasion potential in vitro and metastasis potential in vivo of two groups were compared by Boyden charmber test and metastasis test in the liver of nude mice repectively. Results The purity of uPAR+ group and uPAR- group separated from SMMC-7721 were 90% and 97% respectively,the transmembraned cells of uPAR+ group were much more than that of uPAR- group (P<0.05) in the invasion test in vitro,the mice occurred intrahepatic metastasis,bile duct thrombus and portal vein thrombus in uPAR+ group was significantly more than that in uPAR- group (P<0.05) in the metastasis test in vivo. Conclusion uPAR expression is significantly related with the invasion and metastasis in vitro and in vivo of SMMC-7721 cell line,uPAR may endow hepatoma SMMC-7721 cell line with powerful potential of invasion and metastasis.