Oversea hydrocarbon exploration always faces some problems,such as multiple basin types,different exploration prospects,various exploration degrees,diverse data quantities and geological recognitions.This paper focuses on overseas basins with different exploration degrees and offers a new evaluation system and research method for fast evaluation and risk analysis on hydrocarbon potential.Based on the theory of probability,this new evaluation system evaluates each parameter and core accumulation factor with comprehensive and quantitative assignment,to accelerate geological evaluation.In addition,this paper suggests that source rock evaluation should be the core criterion in screening evaluation of poorexplored basins,and also proposes that both the exploration potential and geological recognition should drive the evaluation for basins with high exploration degrees.This new system and method,which is an effective system for fast basin evaluation,is suggested to be used in oversea evaluation and decision-making objectively,scientifically and efficiently. Oversea hydrocarbon exploration always faces some problems, such as multiple basin types, different exploration prospects, various exploration degrees, diverse data quantities and geological recognitions.This paper focuses on overseas basins with different exploration degrees and offers a new evaluation system and research method for fast evaluation and risk analysis on hydrocarbon potential. this based on the theory of probability, this new evaluation system evaluates each parameter and core accumulation factor with comprehensive and quantitative assignment, to accelerate geological evaluation. addition, this paper suggests that source rock evaluation should be the core criterion in screening evaluation of poorexplored basins, and also proposal that both the exploration potential and geological recognition should drive the evaluation for basins with high exploration degrees.This new system and method, which is an effective system for fast basin evaluation, is suggested to be used in oversea evaluat ion and decision-making objectively, scientifically and efficiently.