Typos is a general term of misspelling and mispronounced characters, which is the common and difficult disease in learning. This book complies characters and words that can be easily written incorrectly or mixed up. Dividing them into three sections--similar pronunciation typos, similar written pattern typos and radical error prone characters--the book includes interpretation, sentence-making and discrimination and relevant exercises. Students are expected to write less or no typos through reading and exercises. The whole book has four volumes and can be used by primary school and junior middle school students.