This study aimed to: (1) determine there is difference of enhancement on students’ mathematical representation ability between whom taught by RME and SAVI Approach, (2) determine there is difference of enhancement on students’ learning motivation between whom taught by RME and SAVI Approach, (3) determine there is interaction between learning approach and prior knowledge of mathematics to the enhancement on students’ mathematical representation ability, (4) determine there is interaction between learning approach and prior knowledge of mathematics to the enhancement on students’ learning motivation. The population was all of students of the private junior high school Pembda 2 Gunungsitoli. Samples were randomly selected of 2 classes numbered 78 students. The Data was analysed by t test and Two Way ANAVA. The result showed that: (1) the enhancement on mathematical representation ability between whom taught by RME approach is better than whom taught by SAVI approach. It can be seen from the result of t test where tcount = 3,261 > ttable = 1,665, (2) the enhancement on learning motivation between whom taught by RME approach is better than whom taught by SAVI approach. It can be seen from the result of t test where tcount = 4,058 > ttable = 1,665, (3) there is not interaction between learning approach and prior knowledge of mathematics to the enhancement on mathematical representation ability. It can be seen from the result of Two Way ANAVA where Frc = 0,274 < Ftable = 3,124, (4) there is not interaction between learning approach and prior knowledge of mathematics to the enhancement on learning motivation. It can be seen from the result of Two Way ANAVA where Frc = 1,322 < Ftable = 3,124.