This book constitutes the refereed proceedings of the 6th CCF International Conference on Natural Language Processing, NLPCC 2017, held in Dalian, China, in November 2017. The 47 full papers and 39 short papers presented were carefully reviewed and selected from 252 submissions.  The papers are organized around the following topics: IR/search/bot; knowledge graph/IE/QA; machine learning; machine translation; NLP applications; NLP fundamentals; social networks; and text mining.