Language is one of the essential characteristics that distinguish humans from other animals. Many aspects of human intelligence are closely related to language: human logical thinking is in the form of language, and the vast majority of human knowledge is also recorded and passed down in the form of language. This chapter gives the definition of natural language processing and introduces the complexity, importance, development history, and upstream and downstream tasks involved. Additionally, it presents an overview of the current state of Chinese NLP, covering task evaluation results, datasets, evaluation methods, and the progress of Chinese pre-trained language models.