Argumentation in writing research articles is very crucial for showing the position of authors in a certain science field, but the social and humanity authors are still lower in skill for argumentation. This research investigated the using and impact of the Genre Based Approach (GBA) in training and mentoring of Research Article writing in improving the skill of argumentation in writing RA. The aim of this study is to describe the activity of learning and teaching by using GBA in training and mentoring of writing RA for social and humanity authors and the impact of this training and mentoring on the skill of argumentation in RAs writing. The material and steps of learning and teaching activity are adapted and modified from Widodo (2006) who stated that the rule of GBA is to prepare, focus, task, evaluate and elaborate. Moreover, Ferris & Hedgcock (2005) also explained that GBA is started from joint construction and independent construction stages when students start to write. The instruments of this research were direct observation and RAs draft analysis. Direct observing is also conducted to record every side of GBA design for teaching writing articles. To find the effect of GBA in training and mentoring to improve argumentative skills, the content analysis to the draft of RAs is conducted. The Result shows that the first the activity of training and mentoring writing RAs by using GBA to improve argumentation skills can be described from prepare, focus, task, evaluate and elaborate. The second finding shows that the participants have competence in writing argumentative for each section of RAS. Thus, it can be concluded that GBA in training and mentoring to write RAs is effective to improve argumentative skills in writing class especially writing RAs class.