It takes two to four years for an adult undergraduate course. The study time of adult undergraduate depends on different majors. Ordinary majors, such as business administration, computer science and law, generally take two years, while some more complicated majors, such as medicine, engineering and psychology, take a relatively long time, taking three to four years. Adult undergraduates usually have three learning forms: correspondence, online education and evening classes. Different learning methods have different requirements for learning time. Correspondence and online education require students to arrange their own study time and progress, so the study time is relatively long, while evening classes are held at night, so the study time is relatively short.