Abstract: Objective This study investigated the inhibitory effects of 15-hydroxyprostaglandin dehydrogenase gene(PGDH) on the proliferation of SW480 colorectal cancer cells. Methods Recombinant plasmid pcDNA3.1-PGDH with PGDH open reading frame was constructed.The SW480 cells were transfected with either pcDNA3.1 or pcDNA3.1-PGDH using LipofectaminTM 2000.The cell growth kinetics and the ability of proliferation in vitro were detected by MTT and colony formation assay.Flow cytometry was applied to analyze the cell cycle. The expression of PGDH protein and the variation of p53 and p21 were detected in SW480 cells were examined by Western blot . Results 　The plasmid of pcDNA 3. 12 PGDH was successfully established. After being t ransfected with this gene, the growth velocity of these t ransfected cells was significantly slower than the parental cell line. Colony formation activity of SW480/pcDNA 3. 12PGDH was 16 % while that of the cont rol cell was 58 % in six well plate ( P < 0. 05) . The activity of anchorage2independent proliferation of SW480/ pcDNA 3. 1 PGDH was lower than that of SW480/ pcDNA 3. 1 in soft agar. Otherwise, the expression of p53 and p21 were higher than cont rol. Conclusion 　PGDH could reduce the abilities of proliferation and of anchorage2independent proliferation of SW480 cells which is through p53 pathway possibility.