Abstract: By analyzing the basic formation factors of the hydrocar- bon reservoir inside metamorphic buried hill,a conception of"dominant lithology"is presented.It is suggested that the dominant lithology can become the reservoir,while the non -dominant lithology will become the barrier in the reservoir inside buried hill..Study on protolith restoration shows that the protolith of non-reservoir rock (amphibolite type) in some areas of Liaohe depression is sedimentary rock,but the amphibolite carries on the bedded structure of the protolith of reservoir rock and becomes the laminar barrier inside the buried hill.On the base of analysis on the hydrocarbon res- ervoir inside metamorphic buried hill in Liaohe depression,it is presented that the hydrocarbon reservoir inside metamor- phic buried hill is characterized by the laminar structure,and then the formation mode of the reservoir inside metamorphic buried hill is established.The exploration ideas as"selecting dominant lithology,searching barrier inside the buried hill and prospecting the reservoir inside the buried hill"are sug- gested,which present a theoretical base for the exploration in hydrocarbon reservoir inside metamorphic buried hill in Liaohe depression.