Abstract: For volatilization loss problems in transportation and storage process, circumstance, tank roof and lateral wall temperature of some fixed roof tank have been tested and analyzed continuously for 24 hours, and the temperature gradient distribution and change of hydrocarbon and omnispace in tank have been recorded meanwhile. The analysis results show that the change of hydrocarbon space temperature is caused by both circumstance temperature and solar radiation, the latter is the main factor when the tank is exposed to sunlight. The temperature gradient of hydrocarbon space decreases gradually from top to bottom. The temperature of oil which is 10 cm below the oil surface is almost stable within 24 h, and the whole oil temperature changes along with the different seasons. The temperature of roof metal has changed greatly within 24 h, while the temperature at sidewall is remaining. According to the heated characteristic of hydrocarbon space and its relationship with oil breathing loss, efficient anti-radiation coating material with high cost can be applied at tank roof and common coating material can be applied at sidewall. Furthermore, reflection thermal-insulation sheets can be installed at tank roof to decrease breathing loss.