Background This study explores effects of budesonide on the proliferation of nasal polyp epithelial cells and expression of the glucocorticoid receptor (GR) alpha in nasal polyp epithelial cells. Methods Primary cultured, purified, and identified the epithelial cells collected from nasal polyps. The proliferation of nasal polyp epithelial cells was examined by a cell counting kit, and expression of GR-alpha mRNA in nasal polyp epithelial cells was examined by reverse transcription polymerase chain reaction, after training nasal polyp epithelial cells in budesonide solution. Results The average survival rate of nasal polyp epithelial cells was the lowest in 1 × 10−6 M budesonide solution (29.284 ± 0.311%), compared with other concentrations. Budesonide at 1 × 10−8 M caused down-regulation of GR-alpha mRNA expression levels at 6 and 12 ours, compared with the 0-hour group (p < 0.001); compared with the 0-hour group, there were significantly lower expression levels of GR-alpha mRNA at both 24 and 48 hours (p < 0.001); Expression of GR-alpha mRNA at either 48 or 12 hours was not significantly different from that at 24 hours. Conclusion Budesonide can significantly inhibit the proliferation of nasal polyp epithelial cells, down-regulate the expression of GR-alpha mRNA in nasal polyp epithelial cells with time dependence.