Genetic Algorithm is based on the biological mechanism of natural selection and heredity, leveraging colony searching technology, and is particularly applicable for the resolution of complicated non-linear problems intractable with traditional searching methods. Timetable problem is a multi-factor optimized decision problem and is typical problem in constitution and planning. It has been proved as a kind of NP-complete problem. According to the character of courses assignment in an university, a kind of codes and fitness function are designed and solved by Genetic Algorithm. With adaptive crossover and mutation probability employed, the experiment verifies that this method is both efficient and effective for the problem.