The results of the preliminary study were obtained from 15 prospective biology teacher students related to the initial abilities that must be possessed to become a teacher and the implementation of learning in science learning. In general, 15 prospective teachers were of the opinion that it was not so different about the ability to have to become a teacher. Based on the results of the preliminary study, prospective teacher students already know the abilities that need to be possessed to become a teacher and in the implementation of learning students must be active but still not showing knowledge related to knowledge that combines content and pedagogical knowledge. One way to analyze the ability of prospective teacher PCK is through filling in documents consisting of Content Representation (CoRe). The data presented in the form of student response questionnaire analysis related to CoRe in terms of education and language and the results of test the validity and reliability of items. For linguistic aspects of CoRe instrument in general CoRe instrument have very high frequency, meaning that CoRe instrument that have been developed are able to be accepted and used properly by prospective biology teacher students at Muhammadiyah Metro University with a percentage 70%. For educational aspects of the CoRe instrument in general CoRe instrument have very high criteria, meaning that the CoRe instrument that have been developed are able to be accepted and used properly by prospective biology teachers at the Muhammadiyah Metro University with a percentage 73,33%.