Scientific process skills are skills that emphasize the learning, activities, and creativity of students to gain knowledge. Skills of the science process are classified into the psychomotor domain whose judgment tends to be neglected or not yet done optimally. The purpose of this research was to describe the science process skill of students class XI IPA on buffer solution material. The type of this research was descriptive research conducted at SMAN 15 Padang. The sample of research was grade XI IPA 5 and XI IPA 6. Instrument in this research was observation sheet to see the level of emergence of science process skill classified in three levels that was: exist and accordingly, exist but not appropriate, and not yet exist. Skills of the process of science seen from the activities of learning in the classroom and practical work that emergence has not developed optimally. Based on the results of data analysis, KPS indicators were existing and appropriate categories of skills that formulate hypotheses and using tools/materials. The KPS indicators in the category existed but were not appropriate is the skills of observing, interpreting, and applying concepts. Furthermore, the KPS indicators wich were not yet come were ask question and communication skills.