The potential of crude oil swelling is dominant mechanism in the development and implementation of carbonated water (CO2 saturated water) flooding as an environmental friendly enhanced oil recovery method. In this study, the volume of crude oil drop in carbonated water (CW) was measured at temperatures of 30, 50 and 80 degrees C and pressures of 500, 1000, 2000 and 4000 psi to investigate the swelling behavior of crude oil during CW flooding. In addition, the variations of dynamic and equilibrium Bond number of CW/crude oil due to dissolution of CO2 in the crude oil are compared to the crude oil/water systems. It is expected that crude oil swelling decreases as temperature increases due to a reduction of the concentration of CO2 in the CW phase in all the studied pressures. However, interesting and unexpected results was observed. That is, the swelling of crude oil drops significantly different in two distinct regions: in the first region (i.e. pressure lower than crossover), the swelling of crude oil decreases when temperature increases; in the second region (i.e. pressure higher than crossover), the behavior of the crude oil swelling versus temperature is in the opposite of that in the first region.