OBJECTIVE To study the effect of Hath1 gene transfer on the proliferation of colonic cancer cells in vitro. METHODS The recombinant plasmid pcDNA3.1(+)-Hath1 was transfected into HT29 colonic cancer cells, and 3 positive cell clones were randomly selected to test the levels of Hath1 mRNA, Muc2 mRNA, Hath1, Muc2, cyclin D1 and p27 by quantitative real-time RT-PCR and Western blotting. The proliferation of the transfected HT29 cells was observed by means of colony formation assay and xenograft growth in nude mice. RESULTS Hath1 significantly down-regulated of cyclin D1 and up-regulate of p27 expressions and inhibited the proliferation of HT29 cells. CONCLUSION Hath1 gene may be an anti-oncogene in colon carcinogenesis.