Abstract: This research aimed to develop the Web-search Based Instructional System Model (WBIS Model), to investigate the results of using the Web-Search Based Instructional System with regard to the problem solving and learning achievements and to examine the opinions of the samples with regard to learning and instruction using the Web-Search Based Instructional System. The research instruments used were: a Web-search Based Instructional System Model (WBIS Model), a problem thinking test with discriminating powers (B) ranging from 0.20-0.53 and a reliability of 0.659; a learning achievement test with discriminating powers ranging from 0.20-0.63 and a reliability of 0.804 and a questionnaire on learners’ opinions with discriminating powers ranging from 0.302-0.671 and a reliability of 0.904. The statistics used in data analyses were percentage, mean, standard deviation; finding out an efficiency of a Web-search Based Instructional System Model (WBIS Model) based on the required efficiency of 80/80 (E₁/E₂) and comparing achievement mean scores using the dependent sample t-test. The results of the study were as follows: the developed Web-search Based Instructional System Model (WBIS Model) consisted of 4 components: model’s principle; model’s objectives of the model as aiming to develop problem solving thinking and learning achievements, the learning-teaching process comprising of 2 stages: the stage of preparation before learning and teaching and the stage of organization of learning-teaching process. There were 6 activities: preparing, presenting situation hypothesizing, searching supporting and making conclusion and measurement and evaluation, the qualified persons viewed about the appropriateness of the components, procedures and activities as a whole at a high level. The developed Web-search Based Instructional System Model (WBIS Model) had an efficiency of 81.18/83.61. The learners showed gains in learning achievement and problem solving thinking before experimenting at 0.01 level of significance. Also, the learners agreed with the learning via the developed Learning-Teaching Model at a high level.