We developed a prototype of web-based instruction(WBI) program to provide more convenient and more effective service to the public health officials. This web-based instruction program had specific objectives on vaccination for the public health officials who were working for national immunization program. This course had 21 chapters composed of hypertext or voice-based instruction. Using the WBI courseware of Korean Officials Trainging Institution(KOTI), 32 public health official volunteers joined this prototype 2 week program in April 2001. A Auestionnaire survey for evaluation of subjective satisfaction and related factors, cyber-education behavior, and internet using behavior was performed in April, 2001. Among the answered 29 subjects, 24 were female(82.8%). Mean age was 36.6% 6.16. 79.3% of the 29 subjects connected internet in their office. The highest frequent study duration was < 1 hr(51.7%) per connection. They represented relatively high subjective satisfaction in education form(78.6%), and contents(85.7%). But 62.3% of these subjects answered the subjective relative effectiveness score(which was as 100 in case of classical lecture form) was lower than 100. The place to connect internet was only statistically significant factor between these two groups in bivariable analysis. But we could not found any significant factors in multivariate analysis. 89.7% of the subjects answered they would like to participate any more WBI courses serviced by Korean National Health Institute. This study had restriction of small sample size.