The episodeⅠof Indosinian movement in the end of the middle Triassic recorded by a unconformity between the middle Triassic and late Triassic in the east part of North China Plate. Unfortunately,it is difficult to distinguish it in its weast part,Ordos Basin,because of the Triassic stratum are generally sequential deposition. Based on the observation of the drilling cores of Yanchang fm., this paper have established the time series of these event sediments,such as sublacustrine fan,seismites, tuff and kerogenous shale. Their climax are all Significant in the beginning of the Chang-7 stage, Consistent with the time of the episodeⅠof Indosinian movement.They are thought important indicators of the episodeⅠof Indosinian movement in Ordos Basin, and suggest that the boundary between Middle Triassic and Upper Triassic may be roughly equivalent the boundary between Chang-7 section and Chang-8 section; Their weakening and reducing trent from southwest to northeast suggest that these event deposits was sedimentary response of Qinling orogeny. The genetic relations of these event sediments and Dickinson triangular diagram reveal that the Indosinian Qinling orogenic process led to the unprecedented changes of Ordos basin, which dynamic was the closed of Paleo-Tethys and the collision between Yangtze plate and the North China plate.