Argumentation skills are one of the skills of the 21st century. The research aims to analyze students' achievement of argumentation skills using the Creative Problem Solving (CPS) model on biodiversity material. Qualitative research with descriptive methods. The research subjects were class X students in one of the Bandung City schools. The purposive sampling technique used 30 students. The argumentation skills question instrument is based on Toulmin's Argumentation Pattern which has level 1-5 criteria containing 12 essay questions. The research results showed that the students' strongest argumentation skills were at level 3 at 63.3 Percent with sufficient criteria and the weakest at level 1 and level 5 with very weak criteria. The criteria for level 1 are very weak, level 2 is weak, level 3 is sufficient, level 4 is strong, and level 5 is very strong. It is important for other education experts to acquire argumentation skills in the learning process.