Penelitian bertujuan untuk mengetahui kualitas argumentasi pada diskusi isu sosiosaintifik “Polemik E. sakazakii” melalui weblog. Metode penelitian bersifat deskriptif. Hasil analisis terhadap kualitas argumentasi menunjukkan secara sosial partisipan mampu mencapai argumentasi level lima, adapun secara individual skor rata-rata mencapai 3. Pengembangan kerangka ‘scaffolding’ diperlukan untuk mempertahankan kualitas argumentasi secara sosial dan meningkatkan kualitas argumentasi secara individual.  This study aims to know the quality of argumentation in sosiosaintific issues discussion "E. sakazakii Polemic" through a weblog. The research method was descriptive. The result showed the quality of argument socially were able to achieve level five, but individually were able to achieve an average score of 3. Development framework ‘scaffolding’ required to maintain the quality of argumentation is socially and to improve the quality of arguments individually.