Water falling film dielectric barrier discharge (WFFDBD) has been widely studied for water treatment, due to its good performance on production of active species, mass transfer of active species from gas phase into liquid phase, and therefore the degradation of pollutants. However, few studies have focused on the production characteristics of active species of WFFDBD. In this paper, the formation characteristics of hydrogen peroxide, ozone and nitrate ions in a WFFDBD reactor powered by bipolar pulsed generator were studied under different electric discharge time, peak pulse voltage, power-frequency, air flow rate, water circulation flow rate, pH value and conductivity. The results show that the concentrations of hydrogen peroxide, ozone and nitrate ions increased with the peak pulse voltage, power supply frequency and water circulation flow rate, but the inputted air flow rate presented different effect on the production of active species. Moreover, the increase in pH value and conductivity led to a decrease in the concentration of hydrogen peroxide, while nitrate ion increased with the water pH value and conductivity. The p-nitrophenol degradation result indicates that both ozone and hydrogen peroxide contribute to its degradation possibly via their reaction into hydroxyl radical.