In the atmospheric-pressure pulsed dielectric barrier discharge

the generation and regulation of reactive oxygen species are of essential importance for their applications in biomedicine and are closely related to the variety of their densities with time in a pulsed period. Hence

it is of necessity to investigate the temporal evolution of reactive oxygen species in a discharge period. We investigated the temporal evolutions of the averaged particle densities of the considered species in the atmospheric-pressure pulsed dielectric barrier discharges in Ar/O2 by means of the numerical simulation based on a 1-D fluid model at oxygen con

centration of 1%. The following significant conclusion can be drawn. Electron e

Ar+

Arr

Arm and Ar* are generated mainly at the rising and falling edges of the applied voltage pulse and are consumed rapidly in the pulse-off time

while reactive oxygen species O

O

2

（

1

Δg） and O

3

still exist largely in the gap in the pulse-off time. Thereby

the pathways of generation and loss of the long-lived reactive oxygen species

i.e.

O

O

2

（

1

Δg） and O

3

have been further investigated

and the averaged particle densities of them as a function of the parameters of the applied voltage pulse have also been calculated

giving the corresponding mechanisms.