NiuTrans.SMT is an open-source statistical machine translation system developed by a joint team from NLP Lab. at Northeastern University and the NiuTrans Team. The NiuTrans system is fully developed in C++ language. So it runs fast and uses less memory. Currently it supports phrase-based, hierarchical phrase-based and syntax-based (string-to-tree, tree-to-string and tree-to-tree) models for research-oriented studies.