This course is to provide students with an overview of natural language processing in Japanese and English by exploring its basic and advanced topics. The processing of text in these languages is the focus of this lecture series. The first half of the course covers natural language processing based on linguistics. Starting from the analysis of morpheme, the smallest unit of language that bears a meaning, students proceed with the processing of larger linguistic units, such as phrase, clause, sentence, and dialogue, or the sequence of sentences. For the middle part of the course, statistical natural language processing is explained, which depends upon statistics that has become popular since 1980's. Various important applications of statistical natural language processing, such as information retrieval and extraction, summarization, machine translation, and search inquiry are introduced during the latter part of the course. The final lecture is for a wrap up of what has been explained in the course to review and discuss its historical perspective and future trend.