Abstract: This paper discusses methods for fault closure studies and its relation to oil-gas migration and accumulation.Qualitative researches focus on the mechanical properties of faults, disposition of rock types on the two sides of a fault surface for the closure fault geometry, fault activity, and its relation to oil-gas trap, as well as the relationship between faulting and tectonic stress field.The Semi-full quantitative research includes such methods as entry pressure measurement, reservoir description, fault closure grading, fault closuge closure grading and comprehensive fuzzy evaluation of fault closures, etc.