KTSP requires authentic assessment as a evaluation technique. One of effective authentic assessment is aportfolio assessment. Unfortunately, portfolio assessment is rarely applied in schools by teachers becauseof the difficulty of preparing a portfolio assessment instrument. With the formulation of the problem asfollows How does the development of portfolio assessment instruments of Indonesian Languagesaccordance SMP’s KTSP at first semester of grade VII, How is the quality of portfolio assessmentinstruments of Indonesian Languages accordance SMP’s KTSP at first semester of grade VII and how theimplementation of portfolio assessment instruments of Indonesian Languages accordance SMP’s KTSP atfirst semester of grade VII. The results showed the development process is according to the modeldevelopment stage Fienrich covering analysis, planning, design stage, development stage, and theimplementation phase. The quality is very fulfilling portfolio assessment instruments with an average87.51% includes predictive validity, content validity, construct validity, and concurrent validity. The impactof the implementation of the impact of student scores very well with the average value of the class to reach87.20, 42.86% student activity showed excellent activity, the activity of 44.44% teachers showed goodactivity, 66.66% teachers' responses agreed with the implementation questionnaire instrument portfolio and49.1% of student responses to the questionnaire also agreed implementation in accordance with thedescription of the portfolio instrument modified Likert scale.