The Triassic-Middle Jurassic sedimentary features in the lower Yangtze region might witness a major tectonic movement-the Indosinian movement. Great changes resulting in the sedimentary environmerit from marine to continental would have taken place during this period. The regular evolution of the sedimentary f acies probably recorded a detail process of development of the tectonic move-ment(folding in particutar) in the region. Besides, the existing lower Yangtze basin is beleived to be a remnant subbasia, and the center and the northern part of the original basin disappeared beneath a possible subduction-collision orogenic belt between the North China and Yangtze plates. The Indosian movement in the lower Yangtze region as an expression of this collisional orogeny, is believed to be a progressive deformation process, showing no difference between the principal and subordinate tectonic phases.