Abstract: Tarim basin has undergone multi-stage tectonic movements, and formed three types composed of six subtypes unconformities. These unconformities were better passages for hydrocarbon migration and favourable places for its accumulation, which were of strong effect of transform action of underlying reservoir quality, but also of destructive effect on early formed reservoirs. In addition, they are favourable for late reservoir-formation because of their reconfining actions.It was the difference, inheritance and migration of unconformity types that controlled the formation, evolution and distribution of petroleum reservoirs. Fault-folded and fold unconformities are the most favourable controlling-oil ones.

Key words: Tarim basin, Unconformity, Type, Characteristics, Reservoir