The main purpose of this project is design and practice embedded recorder performance assessment at elementary school music class More than 400 children enrolled for 4th grade at two elementary schools at Tainan were involved The project is intended to link academic concepts and practice circumstance together The project runned 2 semesters. For moral concerned and also for gathering the problems in the real school setting, no school schedual should be changed to accompany the project. Two embedded assessment tools were developed and used Questionaire were sent to investigate children's reactions and reinforce their reflections This project provides experiences for music education as followed: 1.examples of transform recorder performance criteria into words; 2. linking assessment skill with teaching recorder, 3.Clarify content standard and achievement standards of recorder performance for 4th grade music class through assessment designing, 4examples of concrete and rich feedbacks, 5eight levels of subdivisions for recorder performance of third and fourth grades' requirement, 6 facilitate cooperative learning and self-reflection; 7 statistics available for further discussion, 8. model of research which will benefits university experts and also elementary school teachers and students 21 figures and 4 appendixes are included.