Abstract: Objective: To observe the change of mRNA expression of HoxA3 and HoxA10 gene treated by phenylacetate (PA) in glioma C6 cells. Methods: Astrocytes of rat brain tissue were primarily cultured and C6 cells were cultured in vitro. The expression of HoxA3 and HoxA10 mRNA were detected by semi-quantitative reverse transcription- polymerase chain reaction (RT-PCR) in the presence of specific primers. The difference of Hox gene expression level between before and after treated by PA in C6 cells was analyzed by student t-test. Results: HoxA3 gene had significantic expression in rat brain astrocyte cells and glioma C6 cells before and after treated by PA. HoxA10 gene had no expression in rat brain tissue. There is significantic expression of HoxA10 gene in glioma C6 cells. The expression of HoxA10 gene became weaker in glioma C6 cells after treated by 0.5 mM PA (P<0.05), HoxA10 gene had no expression after treated by 1.0 mmol/L PA in glioma C6 cells (P<0.01). Conclusion: The mechanism of PA action may be correlated with down-regulatated mRNA expression of HoxA10 gene.