Abstract: Based on the analysis of the tectonic evolution and the hydrocarbon accumulation types and distribution characteristics, the preservation conditions of oil and gas reservoirs in Kurdish region of Iraq were studied. The results showed that the oil generation period in Kurdish region was slightly earlier than the trap formation period,oil and gas filling was in the trap formation period, and the fault sealing was still active. After oil and gas accumulation, the tectonic movement continues to transform the oil and gas reservoir, which will damage the oil and gas conservation. Atmospheric fresh water infiltrates into the reservoir and the oxidation makes the density of crude oil increase. The hydrocarbon accumulation was controlled by the preservation condition of hydrocarbon in Kurdish region.