Matrine is the major active component of the traditional Chinese medicine Sophora flavescens, but the molecular mechanisms of matrine on tumor invasion inhibition remain unclear. The aim of this study is to elucidate the effects of matrine on invasion ability of human hepatocellular carcinoma (HCC) cells, matrix metalloproteinase-9 (MMP-9), and nuclear factor (NF)-kappa B expression. The expression activity of MMP-9 was measured by reverse transcription polymerase chain reaction, Western blot, and gelatin zymography analysis. The expression of NF-kappa B was measured by the Western blot analysis. Matrine significantly inhibited MMP-9 expression of SMMC-7721 cells. NF-kappa B inhibitor PTDC induced a marked reduction in MMP-9 expression, and it suggested that NF-kappa B could play an important role in MMP-9 expression. Furthermore, matrine significantly suppressed NF-kappa B expression and the invasion of SMMC-7721 cells. Our results showed that matrine inhibited MMP-9 expression and the invasion of human HCC cells. The inhibitory effects are partly associated with the downregulation of the NF-kappa B signaling pathway.