Abstract： Objective To investigate the relationship between bacteria biofilm and bacterial culture in patients with chronic rhinosinusitis (CRS). Methods Ninety patients with CRS were enrolled in the study. Five patients with deviation of nasal septum and 10 healthy subjects served as controls. Mucosa of uncinate process or near the ostium of the maxillary sinus was obtained during endoscopic sinus surgery. All specimens were processed for bacterial culture and scanned by electron microscopy. Pearson test was performed to analyze the relationship between the presence of bacterial biofilm and the results of bacteria culture. Results The scanning electron microscopy showed bacterial biofilms in 64 (71.1%) out of 90patients with CRS, while the positive rate of bacteria culture in the study group was 66.7% (60/90). No bacterial biofilm and bacterium was detected in the control group and 26 culture-negative individuals in study group. Pearson correlation analysis showed a statistically association between bacterial biofilm and bacterial culture in CRS ( r = 0. 901, P = 0. 000). Conclusion Positive results of bacteria culture are highly correlated with the presence of bacterial biofilm in CRS patients.