This paper describes the submitted discourse parsing system of the natural language group of Soochow University (SoNLP-DP) to the CoNLL 2015 shared task. Our System classifies discourse relations into explicit and non-explicit relations and uses a pipeline platform to conduct every subtask to form an end-toend shallow discourse parser in the Penn Discourse Treebank (PDTB). Our system is evaluated on the CoNLL-2015 Shared Task closed track and achieves the 18.51% in F1-measure on the official blind test set.