The book introduces JavaScript and related CSS, DOM, Ajax, jQuery technologies. It starts from the JavaScript language, explaining images, framework, browser window, form, regular expressions, user events and cookies. Another two chapters are added on the basis of the last edition, elaborating the basic knowledge of the jQuery framework. The book not only introduces the basic knowledge and the use of JavaScript but also analyzes the JavaScript application examples. The book is suitable for the persons that intend to engage in Web development and Web design beginners. It is also a recommended textbook for college courses.