This study aimed to investigate the impact of Parallel teaching on the academic performance of students in the sixth grade in math and their attitude toward school was conducted. The research method was experimental and pretest-posttest with control and experimental groups. Statistical population consisted sixth female students in Tabriz in the academic year 94-95 and the sample size is 70 persons that 35 of them in the control group and 35 patients in the experimental group were exposed. So in the experimental group Parallel teaching was conducted for 2 months and in the control group one teacher was used for teaching. The Analysis of ANCOVA was performed on the math achievement of students in the experimental and control group's shows that the students' mathematics achievement between the experimental and control groups was a significant difference observed