Abstract: According to core analyses test,log parameter interpretation etc,X oilfield Minghuazhen lower segment reservoir internal structural feature and main controlling factors have been analyzed and evaluated comprehensively.The researches show that the heterogeneity of subaqueous distributary channel center is middle,the heterogeneity of subaqueous distributary channel edge is large.The heterogeneity in layer is middle,intrabed and areal heterogeneity is strong.Sedimentary environment and sedimentation are the main factors to affect the heterogeneity of reservoir.