Abstract: The porosity,permeability and attitude of carrier layer have important influences on hydrocarbon migration and accumulation.Case studies have been conducted in the transporting frames of the eastern rift basins.Based on steady filling,the physical property and attitude of carrier layer have been changed so as to analyze their influence on hydrocarbon migration pathway in carrier layer junction.When hydrocarbon migrates to the junction of two carrier layers,the predominant pathway depends on both the physical property and the attitude of each sand layer.The carrier layer with bigger angle and better physical property is much easier to become favorable pathway for hydrocarbon migration.The physical property limit for predominant pathway change in carrier layer junction has been calculated at different angle through theoretic study and experiment.If physical property equals to the critical value,both the two transport layers can work as favorable migration pathway.If physical property is bigger or smaller than the critical value,only one transport layer can be favorable migration pathway.A quantitative model has been established so as to predict favorable pathway in carrier layer junction.