Objective To study the effects of transcription gene sciencing（TGS） and posttranscriptional gene silencing（PTGS） on interfernce of heparanase（HPA） gene in hepatocellular carcinoma cell line SMMC-7721 and its invasion ability. Methods The small interfering（siRNA） of TGS and PTGS covered promoter region and coding region of HPA gene were designed and syntheses， and then transfected into hepatocellular carcinoma cell line SMMC-7721 by neuclear trancfection. HPA expression in both mRNA and protein level were detected by RT-PCR and Western blotting at 48， 72 and 96h， and blank group was set as control. Transwell chamber experiment was used to detect the ability of invasion and migration of hepatocellular carcinoma cell line SMMC-7721 after TGS and PTGS siRNA transfected. Results Both of TGS and PTGS technique could silence HPA gene at mRNA and protein level 48 hours later after siRNA transfection. The expression of HPA gene in PTGS group was recovered 72 hours later after siRNA transfection， but HPA still kept silencing in TGS group. However， the expression of HPA gene in both of TGS and PTGS groups were recovered 96 hours later after gene transfection. The transwell chamber experiment confirmed that TGS and PTGS of HPA gene could reduce the abilities of invasion of SMCC-7721 cell， especially in TGS group. Conclusion TGS can silence HPA gene better compared with PTGS，and significantly decrease the abilities of invasion of hepatocellular carcinoma cell line SMMC-7721.