According to heat-press simulation experiment of source rock and phase diagram，we studied the phase type of hydrocarbon and its evolution characteristics during the stage of generation-discharge and migration-accumulation in Wenliu area，Dongpu depression.The results show that the Es3 source rock hydrocarbon phase stages are varying in different depth attribute to the difference in thermal evolution degree，the phase stages are heavy oil，conventional oil，ethereal oil，condensate oil and wet gas-dry gas.The changes during generating and transporting including gas ex-solution，oil thickening，oil cracking，oil inverse evaporating into gas.Controlling by temperature，pressure and composition，the middle and upper layer major transform is gas ex-solute from oil，and the lower layer transform is oil cracking dominated by temperature and pressure.Based on the former information，combining with the GOR data and hydrocarbon phase state，the law of phase state in vertical sequence is studied，reservoirs in the deeper layer are mainly gas pool，while reservoirs in the middle and upper layer are mainly oil reservoirs and the critical state of oil and gas reservoirs.