Biodegradation of pyridine and phenol was carried out in batch-scale experiment. The kinetics of short-cut denitrification process was studied using a mixture of pyridine and phenol as electron donor and NO₂^--N as electron acceptor. Experimental results showed that pyridine degradation was inhibited in the presence of phenol. Further investigation revealed that the pyridine degradation, no matter whether co-metabolized with phenol, fitted the zero-order kinetics model. However, the COD and NO₂^--N concentrations fitted the double-substrate Monod model, with the predicted and measured values showed a good correlation. The maximum specific degradation rate was 0.0067mg NO₂^--N/(mg MLVSS·h), and the half saturation coefficient for organic substance and nitrite nitrogen were 76.35 mg/L and 0.66 mg/L, respectively.