We constructed Interactive Conceptual Instruction (ICI) model through PDEODE*E tasks (stands for Predict, Discuss, Explain, Observe, Discuss, Explore*, and Explain) for promoting the pre-service physics teachers' understanding on magnetic field. The ICI model consists of four phases; (1) Conceptual focus (2) Use of texts (3) Research-based materials (PDEODE*E tasks) (4) Classroom interactions. The ICI of teaching model has been implemented to seven Physics students who were re-taking (take the course for second times) in the Basic Physics II course as a pilot study. A Field Conceptual Change Inventory (FCCI) comprised of 15 three-tier test items was administered to seven pre-service physics teachers. Students' ideas were elicited by using FCCI and students' worksheets regarding PDEODE*E tasks. The test and worksheet were analyzed in qualitative way. An analysis of collected data has mainly focused on magnetic field conceptions with its subordinate concepts such as magnetic interaction in variety of mediums, magnetic swing (Lorentz law) and rotating magnetic field (Eddy's current). This study concluded that the students' conceptual understanding of the magnetic field increases but a few misconceptions still occurred in seven students' minds.