Abstract: Structural sedimentation is an important factor for changes in accommodation space of a basin, exerting an obvious controlling effect on sedimentation rate and sedimentation system. Structural sedimentation gradient is the characterization value of horizontal variation for basin structural sedimentation in a certain geological period, indicating the variation characteristics of this basin^’s accommodation space during this period. Based on the analysis of structural sedimentation gradients of the second member and third member of the Triassic Xujiahe Formation in Sichuan Basin, it is found that structural sedimentation gradient has an apparent controlling effect on sedimentation system and distribution of sedimentation facies. In the zone with a high structural sedimentation gradient, accommodation space changes quickly with development of water systems while the sedimentation facies changes significantly. In the zone with a low structural sedimentation gradient, accommodation space changes slowly with dissipation of water systems and the sedimentation facies is distributed steadily. Based on the analysis of the fourth member of the Xujiahe Formation in Guang’an region, it is found that structural sedimentation gradient also influences distribution of reservoirs. In the regional zone with a high structural sedimentation gradient, channel hydraulic power is strong owing to a high slope of landform. The physical properties of sandstone reservoirs are relatively desirable. As compared to the basins of other types, the rift basins represented by Nanpu Depression have a high structural sedimentation gradient, basically at 1 to 7 (m/Ma)/km, causing the sedimentation facies to become narrow and change quickly. The length of the subfacies is only 6 to 13 kilometers, with the lithological characters and physical properties changing quickly. The developed favorable reservoirs are small in scale and strong in heterogeneity. In the foreland basins and sag basins represented by the Xujiahe Formation of Sichuan Basin and the Shanxi Formation of Ordos Basin structural sedimentation gradient changes slowly, basically at 0 to 1.5 (m/Ma)/km, leading to large scale of sedimentation system and extensive distribution of sedimentation facies. The length of the subfacies reaches 50 to 150 kilometers, forming large-scale channel delta and enabling favorable reservoirs to be distributed steadily in large areas. These basins are favorable zones for development of large-scale lithological oil and gas areas.