The middle-upper Proterozoic in Hebei-Liaoning depression covers an area of about 70

000 km

2

and is composed mainly of carbonates.A lot of oil shows have been found within the depression.According to the type and abundance of organic matters there

it is sugges-ted that the Gaoyuzhuang

Wumishan

Hongshuizhuang

Tieling and Xiama-ling Formations are all capable of generating hydrocarbons

but the most favour-able source-reservoir-cap assemblage are the Hongshuizhuang

Tieling

Xiama-ling Formations.The maturity of organic matters vary with places.At pre-sent

organic matters in Jibei

Liaoxi and Xuanlong depression are in a status of matured stage

those in Jizhong depression have reached highly matured to wet gas stage

while others in the other basins are in over-matured stage.According to the study of Shuangdong anticline

it is believed that oil was formed mainly in the periods of Indo-China and Yenshan movements.Finally

oil promising areas in the middle-upper Proterozoic are suggested in this paper.