N-Gram（有时也称为N元模型）是自然语言处理中一个非常重要的概念，通常在NLP中，人们基于一定的语料库，可以利用N-Gram来预计或者评估一个句子是否合理。另外一方面，N-Gram的另外一个作用是用来评估两个字符串之间的差异程度。这是模糊匹配中常用的一种手段。本文将从此开始，进而向读者展示N-Gram在自然语言处理中的各种powerful的应用。(N-Gram (sometimes referred to as N metamodel) is a very important concept in Natural Language Processing. Usually in NLP, people can predict or evaluate whether a sentence is reasonable based on a corpus based on N-Gram. On the other hand, another role of N-Gram is to evaluate the degree of differences between two strings. This is a commonly used method in fuzzy matching. This article will begin to show the readers of the various applications of N-Gram in the various powerful in Natural Language Processing.)