Abstract: According to the actual unconformity data of Zhuengaer Basin and the relation of lap-erosion on the upper or lower part of unconformity layer, a new kind of unconformity type demarcation project has been put forward. This kind of project has divided the line unconformity as four kinds of types; onlap/erosion truncation type, concordance/erosion truncation type, onlap/con-cordance type, concordance/concordance type. On the basis of research on the relation of unconformity type with oil-gas migra-lion-accumulation，the upper or lower part of onlap/erosion truncation type are best of all favorableness for accumulation of oil and gas; the upper part of concordance/erosion truncation
type are favorableness for migration of oil and gas , the lower part are favorableness for accumulation of oil and gas;the upper part of onlap/concordance type are favorableness for accumulation of oil and gas, the lower part are favorableness for migration of oil and gas; the upper or lower part of concordance/concordance type are favorableness for而gration of oil and gas，and favorableness for accumulation of oil and gas if the match of fault and fold.

Key words: Zhuengaer Basin, unconformity layer, uncon-fortuity type, oil and gas migration, oil and gas accumulation