Numerical simulations of the oxygen production in the batch Bray-Liebhafsky (BL) oscillating reaction were performed. The dynamic behaviour of the BL reaction was modelled by a scheme suggested by Schmitz and Kolar-Anic, complemented by the physical processes of iodine and oxygen interphase transport. The calculated number and periods of oscillations of the rate of the gaseous oxygen production are in satisfactory agreement with experiment. Oscillations in iodate concentration have been found if some escape of iodine from the batch reactor was allowed.