An explosion accident is possible for process of oil recovery using air injection because of the existence of flammable mixture. So it is necessary to measure the explosion limits and the critical oxygen content of crude oil vapor at different temperatures from 15℃ to 150℃. The measurement result indicated that the explosion limit of crude oil vapor is 4.62%—14.01% at 15℃ and 4.24%—15.62% at 150℃，while the critical oxygen is 13.15% at 15℃ and 12.47% at 150℃. The range of explosion limit widens and the critical oxygen content decreases with temperature increasing. The correlations between explosion limits as well as critical oxygen content and temperature are founded through numerical analysis，which could be used for forecasting the explosion limits and the critical oxygen content of crude oil at different temperatures.