Abstract: Objective To investigate whether 15-deoxy prostaglandin J2 (15d-PGJ2), natural ligand of peroxisome proliferator-activation gamma (PPARγ) receptor, inhibit the growth of human gastric cancer cell and its regulation on the expressions of p27, Skp2, survivin and CD44 in vivo. Methods Human gastric carcinoma MGC803 cells were injected into upper body of right upper limb of 12 nude mice subcutaneously. When small nodules grew, all nude mice were divided into control and experimental group (n= 6) randomly. Control group were given PBS, while the experimental group were given intravenous injection of 15d-PGJ2 every day. Reverse transcription polymerase chain reaction (RT-PCR) and Western blot were used to detect the expressions of p27, Skp2, survivin mRNA and protein in subcutaneously xenografted tumor tissues. Immunohistochemical staining was used to detect CD44 expression and for count the number of CD44-positive cells. Results After 15d-PGJ2 was given for 16 times, the average tumor volume of experimental group(573.86±242.90) mm³, was significantly smaller than that of control group(1244.01±257.81) mm³(P <0.05). The expressions of p27 mRNA and protein in experimental group were much higher than those in control group, while the expressions of Skp2, survivin mRNA and protein in experimental group were lower than those in control group. The rate of CD44 positive cells in experimental group(51.20±12.45)%, was significantly lower than that of control group(85.45±15.45)% (P<0.05). Conclusion 15d-PGJ2 inhibits the growth of human gastric cancer cells and regulates the expressions of p27, Skp2, survivin and CD44 suggesting that 15d-PGJ2 may be effective for treatment of gastric cancer.