The purpose of this study is to develop character assessment instruments to measure the character of junior high school students after obtaining learning by using innovative learning models based on character education. This research is a development research that refers to Borg and Gall‘s development models. The instrument used to measure student character was a self-assessment questionnaire of student character ownership and student character observation sheets. The trial of the use of the instrument was carried out at SMPN 19 Pontianak. Data collected by using questionnaires and unstructured interviews. Data analysis was performed by testing the validity and reliability of the instrument. The results show that the character assessment instruments produced were valid and reliable.