Abstract: Objective To investigate the relationship between the expression of PPARγ and RXRα and the inhibitory effect of pioglizatone , ligands of PPARγ and 9-cis-RA, ligand of RXRα on growth of human digestive carcinoma cell lines(MGC803, LOVO and SMMC7721) in vitro. Methods The Antiproliferative effect was evaluated by cell viability using MTT assay. The mRNA expression of PPARγ and RXRα was semi-quantified by RT-PCR. Results The growth of MGC803 and SMMC7721 cells was significantly inhibited when treated with PGZ and a combination of PGZ and 9-cis-RA , respectively, but no significant inhibitory effect was observed in LOVO cells. The combination group has more inhibitory effect in MGC803 and SMMC7721 cells than PGZ alone (P＜0.01) . PPARγ and RXRα mRNA were both expressed in MGC803，SMMC7721 and LOVO cells, and the expressive level ranked MGC803＞SMMC7721＞LOVO. PGZ significantly up-regulated the expression of PPARγ in MGC803 and LOVO cells, the expression of PPARγ was higher in combination group than PGZ alone(P<0.05). The expression of RXRα in MGC803 and LOVO cells treated with 9-cis-RA was both significantly up-regulated, but has no significant difference between combination group and 9-cis-RA alone. Conclusions It is of necessity that the expression of PPARγ and RXRα in MGC803, SMMC7721 and LOVO cell lines predicts them response to pioglizatone and 9-cis-retinoic acid treatment, the inhibitory effect was different in these three kinds of cell lines, it maybe related to ligands-mediated signal pathway.