With the advent of the 21st century, reforms of science education are taking place all over the world. In order for reform to succeed, it is necessary that careful consideration be paid to policy making, planning of research studies, and implementation of refform efforts. Besides, all stakeholders, including students, teachers, education administrators, and the general public, are expected to have a good understanding and to reach a general consensus of reform rationales, goals, and methods. Therefore, based on the needs for living in the 21st century, this article points out that students will be expected to have scientific literacy including the understanding of key concepts in science, understanding of the nature of science, application of scientific knowledge in daily life, awareness of scientific/technological/societal interactions, application of new technologies in education, abilities in problem-solving, skills for life-long learning, effective communication, congeniality, adaptability, open to changes, etc. In view of the growing acceptance of constructivism in the science education community, the next point mentioned in this article concerns principal ideas of constructivism and the role it plays in science education reform. Finally, in order to improve the teaching and learning of science and mathematics, teaching approaches emphasizing both hands-on and minds-on activities, and cooperative learning, students' individual differences were suggested. It was also pointed out that helping students learn how to learn, to think critically, to be creative, and to develop problem-solving skills are also very important. The fact that the Internet and World Wide Web are developing rapidly, and thus providing extremely powerful tools and facilitating learning environments for science teaching and learning, was noted. Some sciience education resources and projects available on-line were mentioned to illustrate future development and application of computer networking and learning technologies in the areas of science education.