The Douposi Formation in the Micang Mountains, Northeast Sichuan consists of clastic—carbonate mixture, which was supposed to form in a cratonic basin. Based on detailed section measurement, sedimentary environments and provenance were used to analyse and discuss the tectonic setting. Methods: With the help of sedimentary successions, tourmaline electron probe microanalysis and detrital zircon U- Pb dating were carried out on the Douposi sandstones in this paper. Results: In the Micang Mountains, Douposi Formation is characterized by grey limestone or dolostone, purplish thin- bedded siltstone, mudstone and grey fine- grained sandstone, which developed horizontal bedding and nodules. The facies assemblages indicate that the sedimentary environments are supratidal and intertidal zone. Detrital heavy minerals are zircon, tourmaline, rutile and leucosphenite etc, suggesting that the parent rocks were sedimentary and magmatic rocks. The results of tourmaline electron probe microanalysis show that the Douposi sediments are mainly derived from the granitoids and their associated pegmatites and aplites, metapelites, and metapsammites. Detrital zircon geochronology shows that they were derived from 542~520 Ma and 993~731 Ma rocks, which were mainly derived from Gangwana supercontinent and Kangdian oldland. Conclusions: Combined with the rock assemblages, provenance analysis and detrital zircon geochronology, Douposi Formation was deposited in a collisional setting, that is, foreland basin.