To achieve an integrated environment for measurement and instrumentation, we designed and implemented a client/server distributed environment and developed a web-based virtual laboratory system for electronic and digital circuit experiments. Since our virtual laboratory system is implemented to describe the on-campus laboratory, virtual experimental data similar to real experimental data can be obtained through the system. In addition, our web-based virtual laboratory is designed to enhance the efficiency of both the learners and the educators. The learners will be able to achieve high learning standard and the educators save time and labor. The proposed virtual laboratory system is composed of three important sessions: Principle Study Session to explain the concepts and to simulate digital circuit operations, Virtual Experiment Session to provide interactive multimedia contents about the syllabus of off-line laboratory class, Assessment Session and Management System. With the aid of the Management System every session is organically tied up together to achieve maximum learning efficiency. Through our virtual laboratory, the learners will be capable of learning the theories related to electronic circuit experiments and the operation method of the experimental equipments such as multimeters, function generators, digital oscilloscopes and DC power supplies. Also, every activity occurred in our virtual laboratory will be recorded on the database and will be printed out on the preliminary report form. Finally, we have obtained several affirmative effects such as reducing the total experimental hours and the damage rate for experimental equipments.