The purpose of this study is to find out the comparative interest and reading comprehension ability of elementary school students which adopted the School Literacy Movement and non-adopters elementary school students of the School Literacy Movement in Purbalingga district. The research method that used is a comparative method, which is use a survey research design by using independent variables namely School Literacy Movement and dependent variable namely reading interest and reading comprehension ability. The reading interest data was collected using questionnaires and comprehension reading skills were collected using tests. Furthermore, the data were analyzed with statistics using two difference average tests, namely Paired Sample t-test and independent samples t-test. Based on the results of data analysis shows: 1) there are significant differences between interest and understanding reading ability of elementary school students adopting GLS and elementary school students non adopting GLS. The acquisition t value of independent samples t-test that assesses reading interest is 14,373 while the t-table value is 95% significant (0,05). 2) The acquisition t value of independent samples test that assesses comprehension reading ability of 3.436 with a sign of 0.001 <0.05. This shows that the School Literacy Movement has more significant influence on interest and reading comprehension in elementary school students adopting GLS than non-adopting GLS schools.