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Argumentation is a process to understand the complex concepts of science, in which students initiate and justify their claims on certain knowledge. This research aims to know how students' argumentative skills improved by applying teacher's questioning techniques and argumentative assessment through collaborative action research between student teacher who did teaching practicum, assigned biology teacher, and two supervisors. The action research was done in three cycles involving one class consisted of 36 students of Grade Eleventh. Lesson design was developed collaboratively, and teaching practice were by the trainee teacher. In the reflective phase prior to the first cycle, learning process were dominated by teacher, hence students did not have sufficient opportunity to argue. Students were divided into two, 14 students were grouped as low achievement students (LA) and 22 students were high achievement (HA). Teacher questions and students' responses were furtherly coded and interpreted following the level of argumentation. At the end of third cycle, HA and LA students showed a significant change on argumentative skills responded the teacher's questions. However, only four LA students who actively argued. Students from HA groups also indicated the improvement on the level of argumentation skors, where they move from level 1 to 3.  However, only one LA student showed the similar pattern.