Objectives:The Xiajiang Group in Southeast Guizhou is an assembly of siliciclastic rocks interbedded with volcanic clastic rock that show the feature of flysch. It can be divided into the Jialu, Wuye, Fanzhao, Qingshuijiang, Pinglue and Longli formations from bottom to top. This paper focused on the major, trace element and Nd isotope features of the group in order to identify the tectonic environment of western Jiangnan Orogen in Xiajiang period, and further to unravel evolution of the orogen and juxtaposition of Yangtze and Cathaysia blocks. Methods: 21 samples have been analyzed, respectively from Jialu, Wuye, Fanzhao, Qingshuijiang, Pinglue and Longli formations. Of these, pointcounting was performed on 9 coarsegrained sandstone samples from the group. Between 300 to 500 points were point counted in each thin section following the Gazzi—Dickinson method . Major, trace and rare earth elements of 12 finegrained sandstones were measured by XRF and ICPMS, respectively, at the State Key Laboratory of Biogeology and Environment Geology of CUG. Both the accuracy of analysis are >5%. And Nd isotopic analyses are measured by MCICPMS at the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences. The mass fractionation correction for Nd isotopic ratios are based on n(146Nd)/n(144Nd)=0.7219. The measured n(143 Nd)/n(144Nd) ratios of the La Jalla standard are 0.511862±10(2σ). During the analytical process, withinrun errors of precision are estimated to be better than 0.000015 for n(146Nd)/ n(144Nd) in the 95% confidence level. Results: The results show that all the samples rich in Co, La, Ce, Nd, Y and Lu and deplete in Ta and Ni, wth obvious negative Eu anomalies. SmNd isotopic analyses show negative （εNd(t) values of -0.35 to -3.36. Geochemistry features indicate the source rock are dominated by granitic rocks with the infilling of mafic rocks. And they suffered moderate chemical weathering (CIA=52~79) before the deposition. The tectonic discrimination figures show that the basin was located in an active continental margin, which was related to island arc action. Conclusions: This study indicates that the subduction still went on along the western part of Jiangnan Orogen during the Xiajiang period. The Yangtze Block had not collided with the Cathaysia Block at the western part of the Jiangnan Orogen untill the Xuefeng Event. Compared with the time of orogeny at the eastern part of the belt, we suggest that collision between the Yangtze and Cathaysia blocks was diachronous in the trending direction of orogen, commencing initially in the eastern part of orogen before extending to the west.