This study aimed at: (1) determining whether the Concrete-Pictorial-Abstract (CPA) strategy has a positive effect on students' mathematical conceptual understanding (MCU) and students' mathematical representation (MR) on fractions; (2) describing how CPA strategy can improve students' MCU and students' MR on fractions. This research used a mixed method with simultaneous strategy. Sixty-six students participated in the test control group during the quantitative phase. The experimental group employed the CPA strategy teaching method and their test occurred during eight meetings. The descriptive approach was used during the qualitative phase. The members of the experimental group were chosen with certain characteristics in mind. The quantitative data which included MCU and MR were collected using a narrative format. The qualitative data were; (a) students' responses to CPA strategy, (b) group discussion activities, and (c) student products which were collected using (a) thorough interviews, (b) observations collected on forms, and (c) documentation of behaviors. The quantitative data were analyzed using one tailed of MANOVA test with significance level of 5%. The qualitative data were analyzed in 3 stages; (a) data reduction, (b) data presentation, and (c) data verification.