摘要:The purpose of the present study was to determine 9th grade students’ misconceptions on the concepts of diffusion and osmosis and to investigate the effect of making use of concept mapping instruction on overcoming the misconceptions. The experimental study was conducted in two different classes of a high school context with a total of 50 9th grade students in Denizli, Turkey. The concepts of the diffusion and osmosis were taught the students in the experimental group with the instruction designed by making use of concept mapping method whereas these topics were taught to the control group with traditional instruction. The Diffusion and Osmosis Diagnostic Test developed by Odom and Barrow (1995) was given to both groups as pre-test and post-test. The results indicated that after treatment, the average percentage of students in the experimental group holding a scientifically correct view increased 42%, whereas this increased only 15% in the control group.