Abstract: Objective To investigate the gene transcriptional alteration and search for possible molecular mechanism and pathways implicated in the synergy of DAC and PTX against renal cell caroinoma（RCC）. Methods cDNA microarray was performed and coupled with real-time PCR to identify critical genes in the synergistic mechanism of both agents against RCC cells（ACHN and NC 65）. Various patterns of gene expression were observed by cluster analysis. IPA software was used to analyze possible biological pathways and explore the inter-relationships between interesting network genes. Suppression of PI3K/Akt pathway by DAC and/or PTX was clarified by Western blotting. Results Several key regulatory genes were identified and confirmed， such as lymphoid enhancer factor 1， transforming growth factor β induced gene， C-X-C motif ligand 5 and myelocytomatosis viral related oncogene，and they may play a pivotal role in the synergy of DAC and PTX. The PI3K/Akt， amb2 Integrin，IL2-mediated and IL23-mediated pathways include in the synergy of DAC and PTX against RCC. Moreover， PI3K/Akt pathway and other pathways associated with cyclins，DNA replication and cell cycle/mitotic regulation were also associated with the synergy of DAC and PTX against RCC. Conclusion The activation of PI3K/Akt pathway and other genes may participate in the synergy of two agents. The PI3K/Akt pathway could be suppressed synergistically by two agents.