Some research findings showed that Indonesian students' critical thinking skills below average, especially those who have a low academic ability; even though that skills are needed to face this 21st century. There should be a strategy to train students to develop their critical thinking, one of them is by implementing an appropriate learning model. One of the alternatives is Reading-Concept Map-Timed Pair Share (Remap-TmPS) model. This study aimed to find out the effect of Remap-TmPS model and students' different academic ability towards their critical thinking skills on Biology. This research was conducted in Senior High Schools in Batu, East Java, Indonesia. Pretest-Posttest Nonequivalent Control Group Design was employed in this study and 116 students were involved as the participants. There were two experimental classes taught using Remap-TmPs and two control classes taught as well by using conventional learning. Data on students' critical thinking skills were collected using an essay test. The results of the test were assessed using the critical thinking skills' scoring rubric and an ANACOVA test. The research finding showed that students who have the low academic ability in Biology learning who taught by using Remap-TmPS have equal critical thinking skills or the same as students' who have high academic ability who taught by using conventional learning. So, learning Biology using Remap-TmPS can be used as an alternative for students' who have a low academic ability in order to enhance their critical thinking skills.