This quasi-experimental study was conducted to explore what kind of impact a Web-based educational program can have on nursing students and how nursing students react to this educational program. A Web-based computer assisted instruction for maternity nursing practice was developed by researchers using Instruction System Design model and serviced for nursing students on the WWW. To study educational effect of this program on nursing students 30 senior students at a school of nursing were selected They were assigned into experimental and control groups based on their maternity nursing practice schedule. The effect of the Web-based CAI was measured using Achievement score, attitude toward learning experience and attitude toward computer and Internet, and compared between two groups. There were significant differences between two groups in achievement and attitude score. And students in the experimental group showed positive response to the Web-based CAI program. These results suggest that Web-based CAI is useful as a new teaching tool for maternity nursing practice as well as other nursing courses. Comments on program improvement and operational issues were collected from students. These will be used for program improvement in future.