Nangqian basin is the typical representative of the medium-mini-type paleogene basins controlled by the local north-northwest-treading faults and distributing along Jinsha-Red River belt in the northeastern margin of Qinghai-Tibet. Combined with results of field geological investigation, and analysis and determination of samples, as well as the indoor comprehensive study, the paleoclimate characteristics, indications of sedimentary facies, the provenance as well as depositional environment of Gonjo group in Nangqian basin are systematically analyzed in the framework of the basin evolution. Authors conclude that the Gonjo group can be divided into the three-stage structure, and the depositional environment is the alluvial fan - river - lake - delta environment; the complex conglomerate gravel composition, the poorly sorted and rounded sandstone, and the fillings being the sub-angular shaped inequigranular grit , the calcite cement or the ferruginous cement indicate that the sedimentary environment is proximal and quickly accumulated, and the paleocurrent direction is versatile; the depositional environments belong to warm and moist-dry climate with strong evaporation.