With the rapid development of technology, more and more network courses, supported by computer technology, are designed and developed in colleges and universities in China. It is a significant revolution which reshapes traditional teaching and learning. These user-friendly network courses facilitate instructional settings or learning environment for students' self-learning, sharing information, asking questions, sending each other e-mails and so on. The paper shows our practical research on how to design and develop network English course for preschool teachers by use of Blackboard software, and how to cultivate students' self-learning abilities and set up a assessment system in order to enhance students learning and optimize' their learning environment.