Abstract: Three 3rd-order sequences and eight system tracts are recognized in two outcrop sections of the Middle and Upper Cambrian in Danzai and Sandu，eastern Guizhou province．Because of the tectonic fluctuation activity，the sedimentary environments of the two outcrops changed and the Platform evolved from ramp shelf in the Middle Cambrian to rimmed shelf in Upper Cambrian．Since the late of Middle Proterozoic Era，the ocean crust evolved to continental crust gradually in Guizhou area．Therefore，there were two sedimentary models：a broad open sea shelf model with ramp platform and flat floor，formed in the Middle Cambrian；and a platform (ramp)-open sea(basin)sedimentary model，shaped in the Upper Cambrian．The sequence cycles was controlled by the evolution of regional tectonics，and the sedimentary sequence characters are very important to the analysis of sedimentary environment．