The purpose of this study was to investigate the effects of a Computer-Assisted Instruction designed according to 7E model of constructivist learning(CAI7E) related to "electrostatic'' topic on physics student teachers' cognitive development, misconceptions, self-efficacy perceptions and attitudes. The study was conducted in 2006-2007 academic year and was carried out in three different classes taught by the same teacher, in which there were 79 2nd, 3rd and 4th grade university students, in central city of Diyarbakir in Turkey. An experimental research design including the electrostatic achievement test (EAT), the electrostatic concept test (ECT), physics attitude scale (PAS) and self-efficacy perception scale (SEPS) was applied at the beginning and at the end of the research as pre-test and post-test. After the treatment, general achievement in EAT increased (P<0.05), but not all of subgroup. Difference between pre-test and post-test both knowledge and application levels of cognitive domain was found significant (P<0.05), but not in comprehension level. This result showed that using CAI7E in teaching electrostatic topic was very effective for physics student teachers already learned this topic in several physics course to reach knowledge and application levels of cognitive domain. Analysis of electrostatic concept test (ECT); CAI7E changed students' misconceptions related to electrostatic and electric field positively (P<0.05) and additionally change was found in SEPS (P<0.05). It was also found out that there was no change about students' attitudes towards physics (P>0.05). [See the related article: "A Physics Lesson Designed According to 7E Model with the Help of Instructional Technology (Lesson Plan)" in ERIC at EJ886456.]